Gantry mechanism and synchronous error compensation method thereof

Abstract

The application relates to the technical field of gantry mechanisms, and particularly provides a gantry mechanism and a synchronous error compensation method thereof, which comprises a crossbeam and a gantry, the crossbeam comprises a base, a sliding plate, a motor, a grating ruler and a reading head, the sliding plate is arranged above the base, the sliding plate is driven to move along the base by the motor, and the grating ruler and the reading head are used for determining the position coordinates of the sliding plate; the two ends of the gantry are both provided with fixed plates, the fixed plates are provided with inward grooves along the axis of the gantry, the protrusions on the two sides of the grooves are connected through spring sheets, the crossbeam is connected with the outer surfaces of the spring sheets, so that the flexible connection with the gantry is realized; the two driving motors of the gantry adopt a master-slave control mode, the position deviation of a driven motor is measured based on a driving motor as a reference, the position deviation of the driven motor is compensated, and the accurate synchronization of the two sides of the gantry is realized.

Description

Technical Field

[0001] This invention relates to the field of gantry mechanism technology, and specifically provides a gantry mechanism and a method for compensating for its synchronization error. Background Technology

[0002] In the field of precision machining, gantry mechanisms are commonly used for equipment requiring large stroke and high positioning accuracy. A gantry mechanism typically consists of two X-axis mechanisms and one Y-axis mechanism. The two X-axis mechanisms are arranged in parallel, while the Y-axis mechanism, also known as the gantry frame, is vertically positioned above the two X-axis mechanisms. This dual X-axis configuration ensures the stability and high positioning accuracy of the gantry mechanism during large stroke movements.

[0003] Existing gantry mechanisms are generally classified into single-drive and double-drive types based on their drive method. Single-drive gantry mechanisms are driven by a motor on one X-axis, with the motorized X-axis acting as the driving axis and the other X-axis as the driven axis providing support. Double-drive gantry mechanisms are driven synchronously by both X-axis, each equipped with a motor. Furthermore, in both single-drive and double-drive gantry mechanisms, the Y-axis is fixedly connected to the moving parts of the two X-axis. Due to manufacturing and assembly errors, it is difficult to achieve perfect perpendicularity between the Y-axis and X-axis. Since the moving parts of the Y-axis and X-axis are fixedly connected, the perpendicularity error between the Y-axis and X-axis is difficult to correct after the equipment leaves the factory, resulting in a permanent deviation in the positioning accuracy of the gantry mechanism.

[0004] Furthermore, in single-drive gantry cranes, only one X-axis is driven, while the other X-axis requires forced movement, leading to asynchrony in the movement of the two X-axis. In dual-drive gantry cranes, differences in the initial manufacturing and assembly of the dual X-axis, variations in wear and maintenance, and the combined effects of mechanical coupling and heat generation between the two X-axis can result in differences in the electrical, mechanical, and dynamic characteristics of the parallel dual X-axis. These differences cause asynchrony in the movement of the two axes during gantry crane operation. Therefore, in both single-drive and dual-drive gantry cranes, the movement of the dual X-axis will produce a certain degree of synchronization error. This synchronization error causes the Y-axis to be constantly subjected to unbalanced forces, remaining under constant stress. Over prolonged operation, the strength of the Y-axis will inevitably be affected, leading to deformation. Thus, synchronization error reduces the overall system control and positioning accuracy of the gantry crane, and in severe cases, can even cause drastic deformation of the Y-axis, damaging the equipment and causing safety accidents. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a gantry mechanism that uses spring plates to achieve a flexible connection between the gantry frame and the crossbeam. The spring plates have sufficient strength to support the gantry frame while also being able to withstand a certain amount of elastic deformation, providing elastic deformation to protect the gantry frame from being affected when the dual-axis gantry is out of sync. Furthermore, a synchronization error compensation method for the gantry mechanism is proposed. Through a master-slave control mode, the position deviation of the driven motor is compensated, effectively realizing closed-loop control between the position information and the motor, thereby achieving precise synchronization between the two sides of the gantry frame.

[0006] The gantry mechanism provided by the present invention includes: a first crossbeam, a second crossbeam, and a gantry frame, wherein the first crossbeam and the second crossbeam are parallel, and the gantry frame is perpendicular to the first crossbeam and the second crossbeam;

[0007] The first crossbeam includes a first base, a first sliding plate, a first motor, a first grating ruler, and a first reading head. The first sliding plate is disposed above the first base and is driven by the first motor to move along the first base. The first grating ruler is disposed along the first base, and the first reading head is disposed on the first sliding plate to determine the position coordinates of the first sliding plate.

[0008] The second crossbeam includes a second base, a second sliding plate, a second motor, a second grating ruler, and a second reading head. The second sliding plate is positioned above the second base and is driven by the second motor to move along the second base. The second grating ruler is positioned along the second base, and the second reading head is positioned on the second sliding plate to determine the position coordinates of the second sliding plate.

[0009] Both ends of the gantry frame are equipped with fixing plates. The fixing plates have inward grooves along the axis of the gantry frame. The protrusions on both sides of the grooves are connected by spring plates. The first and second crossbeams are connected to the outer surface of the spring plates to achieve a flexible connection with the gantry frame.

[0010] Preferably, the first crossbeam and the second crossbeam are connected to the spring sheet via a fixing block.

[0011] Preferably, an adjustment mechanism is also provided, which is disposed on the first sliding plate and / or the second sliding plate. The adjustment mechanism includes an adjustment base and an adjustment bolt. The adjustment bolt is threadedly connected to the adjustment base and passes through the adjustment base to abut against the fixed block. By rotating the adjustment bolt, the fixed block and the gantry are pushed to adjust the vertical relationship between the gantry and the first and second crossbeams.

[0012] Preferably, the spring sheet is made of 1.4310 stainless steel.

[0013] Preferably, the gantry includes a third base, a third sliding plate, and a third motor. The third sliding plate is disposed above the third base, and the third motor drives the third sliding plate to move along the third base.

[0014] A method for compensating synchronization errors in a gantry mechanism includes the following steps:

[0015] S1: A camera is installed on the third sliding plate of the gantry, and a calibration plate is placed in the working area of ​​the gantry mechanism;

[0016] S2: Control the first and second motors to move to the working zero position; control the gantry mechanism to move the center of the camera to the first calibration point of the calibration plate; use the third motor to move the camera along the gantry to the second calibration point of the calibration plate, adjust the calibration plate to ensure that the spatial position of the first calibration point remains unchanged, and make the center of the camera coincide with the second calibration point;

[0017] S3: Select the third calibration point on the calibration plate. The line between the third calibration point and the first calibration point is perpendicular to the line between the second calibration point and the first calibration point. Calculate the reference distance Xn between the first calibration point and the third calibration point.

[0018] Move the camera's center to the first calibration point on the calibration plate, control the first and second motors to move a reference distance Xn, and measure the error distance ΔXn between the camera's center movement and the third calibration point.

[0019] S4: Control the first motor or the second motor as the active motor and the second motor or the first motor as the driven motor; use the first motor or the second motor as a reference to perform linear compensation on the second motor or the first motor, with a unit distance compensation value of ΔXn / Xn.

[0020] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0021] This invention achieves a flexible connection between the gantry frame and the crossbeam by incorporating spring plates. This connection method allows for a certain degree of buffering during movement, thereby reducing the assembly precision requirements of the gantry mechanism and the rigidity requirements of the gantry frame material. Overall, it simplifies the design of the gantry mechanism and makes it easier to correct the perpendicularity between the gantry frame and the crossbeam. Furthermore, during the movement of the gantry mechanism, the spring plates can absorb the asynchronous torque of the motors on both sides of the gantry frame, eliminating synchronization errors. In addition, the two drive motors of the gantry frame in this invention adopt a master-slave control method, using the active motor as a reference to compensate for the position deviation of the driven motor. Position information and motor control achieve closed-loop control, thereby achieving precise synchronization of the two axes, protecting the gantry frame from the continuous effects of unbalanced torque, and thus improving its service life. Attached Figure Description

[0022] Figure 1 This is a structural diagram of a gantry mechanism provided according to an embodiment of the present invention;

[0023] Figure 2This is a connection structure diagram of the crossbeam and gantry frame provided according to an embodiment of the present invention;

[0024] Figure 3 This is a cross-sectional view of the connection structure between the beam and the gantry frame provided in an embodiment of the present invention;

[0025] Figure 4 This is a structural diagram of the adjustment mechanism provided according to an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the synchronization error compensation of the gantry mechanism provided in an embodiment of the present invention.

[0027] The reference numerals in the figures include:

[0028] Gantry frame 1, first fixing plate 11, second fixing plate 12, first spring plate 13, second spring plate 14;

[0029] First crossbeam 2, first base 21, first sliding plate 22, first motor 23, first grating ruler 24, first reading head 25, first fixing block 26;

[0030] Second crossbeam 3, second base 31, second sliding plate 32, second motor 33, second grating ruler 34, second reading head 35, second fixing block 36;

[0031] Adjustment mechanism 4, adjustment base 41, adjustment bolt 42;

[0032] Camera 5, calibration board 6. Detailed Implementation

[0033] In the following description, embodiments of the invention will be described with reference to the accompanying drawings. In the description below, the same modules are denoted by the same reference numerals. Where the same reference numerals are used, their names and functions are also the same. Therefore, their detailed description will not be repeated.

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0035] like Figure 1As shown, this embodiment of the invention provides a gantry mechanism, mainly composed of a beam group and a gantry frame 1. The beam group includes a first beam 2 and a second beam 3 with identical structures. The first beam 2 and the second beam 3 are at the same height and parallel to each other in the same horizontal plane. The gantry frame 1 is located above the first beam 2 and the second beam 3, and is perpendicular to the first beam 2 and the second beam 3 respectively. In the following text, the axial direction of the first beam 2 and the second beam 3 is defined as the X direction, and the axial direction of the gantry frame 1 is defined as the Y direction.

[0036] Among them, such as Figure 2 As shown, the first crossbeam 2 includes a first base 21, a first sliding plate 22, a first motor 23, a first grating ruler 24, and a first reading head 25. The first base 21 is a fixed structure, and its upper surface is provided with double-row slide rails. The first sliding plate 22 is located above the first base 21, and its lower surface is provided with double-row sliders. These sliders cooperate with the double-row slide rails on the first base 21. The first sliding plate 22 can perform reciprocating linear motion along the axis on the first base 21 through the double-row sliders. The first motor 23 is also installed on the lower surface of the first sliding plate 22, which drives the first sliding plate 22 to perform reciprocating linear motion on the first base 21. The first motor 23 can be a linear motor, a servo motor, a stepper motor, etc.

[0037] A first grating ruler 24 is also provided on the inner and / or outer edge of the first base 21, and a first reading head 25 corresponding to the first grating ruler 24 is also provided on the first sliding plate 22. The first grating ruler 24 is laid along the axial direction of the first crossbeam 2, and the first reading head 25 is set towards the first grating ruler 24 to read the position information on the first grating ruler 24 and feed back the reading information. The output torque of the first motor 23 is adjusted based on the reading information. The position information and moving distance of the first sliding plate 22 can be accurately determined by the first grating ruler 24 and the first reading head 25. The first grating ruler 24 is designed with a zero point as the absolute reference position for the axial direction of the first crossbeam 2.

[0038] like Figure 4 As shown, the second crossbeam 3 includes a second base 31, a second sliding plate 32, a second motor 33, a second grating ruler 34, and a second reading head 35. The second base 31 is a fixed structure, and its upper surface is provided with double-row slide rails. The second sliding plate 32 is located above the second base 31, and its lower surface is provided with double-row sliders. These sliders cooperate with the double-row slide rails on the second base 31. The second sliding plate 32 can perform reciprocating linear motion along the axis on the second base 31 through the double-row sliders. The second motor 33 is also installed on the lower surface of the second sliding plate 32, which drives the second sliding plate 32 to perform reciprocating linear motion on the second base 31. The second motor 33 can be a linear motor, a servo motor, a stepper motor, etc.

[0039] A second grating ruler 34 is also provided on the inner and / or outer edge of the second base 31. A second reading head 35 corresponding to the second grating ruler 34 is also provided on the second sliding plate 32. The second grating ruler 34 is laid along the axial direction of the second crossbeam 3, and the second reading head 35 is set towards the second grating ruler 34 to read the position information on the second grating ruler 34 and feed back the reading information. The output torque of the second motor 33 is adjusted based on the reading information. The position information and moving distance of the second sliding plate 32 can be accurately determined by the second grating ruler 34 and the second reading head 35. The second grating ruler 34 is designed with a zero point as the absolute reference position of the axial direction of the second crossbeam 3.

[0040] like Figure 3 As shown, fixing plates are provided on both sides of the gantry frame 1. The fixing plate near the first crossbeam 2 is the first fixing plate 11, and the fixing plate near the second crossbeam 3 is the second fixing plate 12. Both the first fixing plate 11 and the second fixing plate 12 have grooves running inward along the axis of the gantry frame 1, and spring plates are protruding on the outside of the grooves. The spring plates are oriented in the same direction as the fixing plates, and the elastic deformation direction of the spring plates is along the axis of the gantry frame 1. The first spring plate 13 is installed at the first fixing plate 11, and the second spring plate 14 is installed at the second fixing plate 12. Specifically, the upper and lower ends of the first spring plate 13 are fixed to the first fixing plate 11 by bolts, or they can be connected by welding. The middle part of the first spring plate 13 can deform in the groove in the middle of the first fixing plate 11. The fixing method of the second spring plate 14 and the second fixing plate 12 is exactly the same as described above.

[0041] A first fixing block 26 is also connected to the upper surface of the first sliding plate 22 of the first crossbeam 2. The first fixing block 26 and the first sliding plate 22 are connected by bolts. The first sliding plate 22 is connected to the middle part of the outer surface of the first spring plate 13 through the first fixing block 26 to achieve a flexible connection between the gantry frame 1 and the first crossbeam 2. When the first motor 23 and the second motor 33 drive the gantry frame 1 to move, because the first spring plate 13 is elastic and the first fixing plate 11 has a groove to accommodate the deformation of the first spring plate 13, a buffer area is formed between the gantry frame 1 and the first crossbeam 11. The connection method between the second fixing block 36 of the second crossbeam 3 and the second spring plate 14 is the same as described above, and it is also used to form a buffer area.

[0042] The gantry frame 1 is connected to the first crossbeam 2 and the second crossbeam 3 using spring plates. These spring plates provide sufficient strength to support the gantry frame 1 while also withstanding a certain degree of elastic deformation. This allows for elastic deformation when the first motor 23 and the second motor 33 move asynchronously, protecting the gantry frame 1 from interference. The elastic modulus of the spring plates is designed based on the dynamic performance of the gantry mechanism. The presence of the spring plates absorbs a certain amount of axial error in the gantry frame 1, reducing the difficulty of machining the axial dimensions and assembly. Furthermore, it effectively reduces the impact of the gantry frame 1 on the first and second crossbeams 2 and 3 during movement, reducing noise and vibration and extending the equipment's lifespan. Simultaneously, the elasticity of the spring plates makes the gantry frame 1 more stable during movement, avoiding swaying or inaccurate displacement caused by rigid connections.

[0043] In a preferred embodiment, both the first spring plate 13 and the second spring plate 14 adopt a plate-like structure. In practical applications, the dimensions, shape, and elastic modulus of the first spring plate 13 and the second spring plate 14 can be adjusted according to the specific needs of the gantry mechanism to meet different usage requirements. The elastic modulus of the spring plate is related to its material. In this embodiment, the spring plate is made of stainless steel, specifically 1.4310 stainless steel. In addition, other types of spring plate materials, such as high-strength steel and aluminum alloy, can also be considered to achieve higher performance and lower cost.

[0044] In a preferred embodiment, the gantry frame 1 is also provided with a third base, a third sliding plate and a third motor. The third sliding plate is also located above the third base. The third sliding plate is driven by the third motor to move along the third base. During the movement of the gantry frame 1 as a whole along the first crossbeam 2 and the second crossbeam 3, the third sliding plate can also move along the gantry frame 1.

[0045] The gantry mechanism is also equipped with an adjustment mechanism 4 for correcting the verticality of the gantry frame 1 and the crossbeam group. The adjustment mechanism 4 is located on one side of the first crossbeam 2 or the second crossbeam 3, or both the first crossbeam 2 and the second crossbeam 3 are equipped with an adjustment mechanism 4.

[0046] like Figure 4As shown, in this embodiment, only the adjustment mechanism 4 provided on one side of the second crossbeam 3 is described as an example. The adjustment mechanism 4 consists of an adjustment base 41 and an adjustment bolt 42. The adjustment base 41 is fixed on the second sliding plate 32 and can be fixed by means of integral molding or welding, which have high connection strength. The adjustment base 41 has a lateral threaded hole, which is matched with the adjustment bolt 42. The adjustment bolt 42 is screwed into and passes through the threaded hole, and the adjustment bolt 42 abuts against the side of the second fixed block 36. The abutment direction is perpendicular or approximately perpendicular to the axial direction of the gantry frame 1. Since the second fixed block 36 and the second sliding plate 32 are fixed by bolt connection, when the bolt is not fully tightened, the second fixed block 36 can be pushed slightly by rotating the adjustment bolt 42 to adjust the vertical relationship between the gantry frame 1 and the second crossbeam 3, reducing minor errors caused by factors such as machining and assembly. The adjustment range of the adjustment mechanism 4 is small and is only suitable for high-precision small-range correction of the gantry frame 1 and the second crossbeam 3.

[0047] Based on the above structure, this embodiment of the invention also proposes a method for correcting the perpendicularity of the gantry frame 1 to the first crossbeam 2 and the second crossbeam 3. The correction process is as follows:

[0048] S1: Initial reset of the first crossbeam 2 and the second crossbeam 3: The first sliding plate 22 is driven by the first motor 23 to move to the zero mark position of the first grating ruler 24; the second sliding plate 32 is driven by the second motor 33 to move to the zero mark position of the second grating ruler 34, and the position of the first sliding plate 22 at this time is recorded as X10 and the position of the second sliding plate 32 is recorded as X20.

[0049] S2: Place the gantry frame 1: After determining the initial positions of the first sliding plate 22 and the second sliding plate 32, place both ends of the gantry frame 1 on the first sliding plate 22 and the second sliding plate 3, with the two ends of the gantry frame 1 located at the initial position X10 of the first sliding plate 22 and the initial position X20 of the second sliding plate 32, respectively. At this time, the gantry frame 1 is not yet fixed to the first sliding plate 22 and the second sliding plate 32.

[0050] S3: Coarse adjustment of the verticality of gantry frame 1: Due to the influence of structural tolerances, i.e. assembly errors, the initial position X10 of the first sliding plate 22 and the initial position X20 of the second sliding plate 32 are likely not on the same vertical line. Therefore, the verticality of gantry frame 1 is adjusted with the initial position X10 of the first sliding plate 22 as the reference point.

[0051] First, ensure that the end of the gantry frame 1 connected to the first sliding plate 22 remains at position X10. Use a high-precision right-angle ruler or similar instrument to align the gantry frame 1 perpendicular to the first crossbeam 2, and then fix the gantry frame 1 to the first sliding plate 22. Since the angle of the gantry frame 1 will change during this process, the other end of the gantry frame 1 will move slightly relative to its initial position X20. This movement is denoted as ΔX20. The other end of the gantry frame 1 should then move to the position X20 + ΔX20. Finally, push the second fixing block 36 by ΔX20, aligning the mounting hole at the other end of the gantry frame 1 with the mounting hole of the second fixing block 36, thus fixing the other end of the gantry frame 1 to the second fixing block 36 and the second sliding plate 32.

[0052] S4: Fine adjustment of the verticality of gantry 1: Use a high-precision right-angle ruler to measure the verticality between gantry 1 and the second crossbeam 3. If the verticality is qualified, the verticality correction work is completed directly. If there is a slight deviation, adjust the position of the second fixing block 36 again by adjusting the structure 4, and further adjust the verticality between gantry 1 and the second crossbeam 3 to complete the verticality correction work.

[0053] It is important to note that during verticality adjustment, the output current of the first motor 23 and the second motor 33 needs to be monitored in real time. If the output current is greater than the set value, it indicates that the torque on the motor is too large, and the verticality between the gantry 1 and the second crossbeam 3 cannot be corrected by fine adjustment. The position of ΔX20 needs to be readjusted. This process may need to be repeated multiple times until the output current of both the first motor 23 and the second motor 33 is less than the set value, and the verticality meets the design requirements. After the verticality adjustment is completed, the position X20+ΔX20 is taken as the zero position of the second crossbeam 3 during operation. That is, when the initial position of the first sliding plate 22 is X10, the initial position of the second sliding plate 32 is X20+ΔX20. In subsequent operations, the second crossbeam will always start from this position. X20+ΔX20 is equivalent to the actual zero mark position of the second grating ruler 34, thus ensuring the consistency and stability of verticality during repeated operations.

[0054] Since the gantry mechanism is driven by a dual-axis system via the first motor 23 and the second motor 33, therefore, as Figure 5 As shown in the figure, this embodiment of the invention also provides a synchronization error compensation method for a gantry mechanism to eliminate dual-axis synchronization error, comprising the following steps:

[0055] S1: Placement of Calibration Plate 6: First, install camera 5 on the third sliding plate of gantry 1. Camera 5 can move along the axis of gantry 1 with the third sliding plate, i.e., achieve Y-axis movement. A high-precision calibration plate 6 is placed in the working area of ​​the gantry mechanism, i.e., below the movement path of gantry 1. The calibration plate 6 has n×m calibration points. Along the X direction, there are n rows; along the Y direction, there are m columns.

[0056] S2: Adjust the parallelism of calibration plate 6: First, the calibration plate 6 and the gantry 1 need to be adjusted to be parallel to each other. Power the gantry mechanism and control the first motor 23 and the second motor 33 to move to the working zero position, that is, X10 and X20+ΔX20 after the perpendicularity correction.

[0057] The gantry 1 is driven by the first motor 23, the second motor 33 and the third motor to move the center of the camera 5 to coincide with the first calibration point on the calibration plate 6. In this embodiment, the selected point a11 is the first calibration point.

[0058] While keeping the first motor 23 and the second motor 33 stationary, move the camera 5 so that its center coincides with the second calibration point. The second calibration point is in the same row as the first calibration point but in a different column, and the distance between the second calibration point and the first calibration point should be as far as possible. Therefore, in this embodiment, point am1 is selected as the second calibration point. Since the calibration plate 6 should not be parallel to the gantry 1 at this time, when the center of the camera 5 and the second calibration point am1 have the same Y-coordinate, there will be a distance in the X-coordinate. At this time, while keeping the spatial position of the first calibration point a11 unchanged as much as possible, adjust the calibration plate 6 so that the center of the camera 5 coincides with the second calibration point am1.

[0059] While keeping the first motor 23 and the second motor 33 stationary, move the camera 5 so that the center of the camera 5 returns to position a11. Confirm whether a11 is aligned with the center of the camera. If they are aligned, complete the parallelism adjustment of the calibration plate 6 and the gantry 1. If a11 is not aligned with the center of the camera, repeat the above process S2 until the calibration plate 6 and the gantry 1 (Y-axis) are parallel.

[0060] S3. Calculate the maximum synchronization deviation between the first motor 23 and the second motor 33: Drive the gantry 1 using the first motor 23, the second motor 33, and the third motor to make the center of the camera 5 coincide with a11. Read or measure the distance between the third calibration point and the first calibration point a11 on the calibration plate 6. The third calibration point and the first calibration point a11 need to be in the same column but not in the same row, and they should be as far apart as possible. In this embodiment, a1n is selected as the third calibration point. Calculate or read the distance Xn between the first calibration point a11 and the third calibration point a1n.

[0061] The first motor 23 and the second motor 33 are controlled to move synchronously according to a set distance Xn. Due to the synchronization error when the two motors move simultaneously, after the movement, the center of the camera 5 will inevitably deviate from the distance a1n in the X direction, denoted as ΔXn. This deviation is the maximum synchronous positional deviation between the first motor 23 (X1 axis) and the second motor 33 (X2 axis) within the working range of the gantry mechanism. ΔXn is a relative quantity, and it will change when the distance between the first calibration point and the third calibration point is different.

[0062] S4: Eliminating Synchronization Error: The first motor 23 and the second motor 33 of the gantry mechanism are controlled in a master-slave manner, with either the first motor 23 or the second motor 33 as the driving motor and either the second motor 33 or the first motor 23 as the driven motor. In this embodiment, the first motor 23 is described as the driving motor. Based on the displacement of the first motor 23, the motion of the second motor 33 is linearly compensated, with a unit distance compensation value of ΔXn / Xn. Assuming the gantry 1 moves a distance of Xm, then the moving distance of the first motor 23 is also Xm. Linear compensation is then applied to the second motor 33, which, in addition to being driven, requires an active compensation distance of (ΔXn / Xn)Xm. This ensures that the positions of the first motor 23 and the second motor 33 are synchronized during movement, achieving synchronous control.

[0063] After the aforementioned synchronization error compensation, the gantry mechanism resolves the asynchrony issue during the start and stop of the dual drive motors. When the gantry mechanism accelerates or decelerates, the time difference in kinetic energy transmission can still cause the first motor 23 and the second motor 33 to become out of sync. However, in this application, the gantry frame 1 and the crossbeam assembly are connected by spring plates. These spring plates possess elasticity and deformation capacity, effectively absorbing asynchronous torques and maintaining synchronous movement of the two shafts. Furthermore, after the first motor 23 and the second motor 33 start and stop, this invention controls a single shaft through position compensation. Closed-loop control is achieved between the position information and the motors, continuously adjusting the motor positions to ensure the actual position matches the target position, thus achieving precise synchronous movement and improving the accuracy and stability of the gantry mechanism.

[0064] Although embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0065] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for compensating synchronization errors in a gantry mechanism, characterized in that, The synchronization error compensation method of the gantry mechanism is based on the gantry mechanism, which includes: A first crossbeam, a second crossbeam, and a gantry frame, wherein the first crossbeam and the second crossbeam are parallel, and the gantry frame is perpendicular to the first crossbeam and the second crossbeam; The first crossbeam includes a first base, a first sliding plate, a first motor, a first grating ruler, and a first reading head. The first sliding plate is disposed above the first base and is driven by the first motor to move along the first base. The first grating ruler is disposed along the first base, and the first reading head is disposed on the first sliding plate to determine the position coordinates of the first sliding plate. The second crossbeam includes a second base, a second sliding plate, a second motor, a second grating ruler, and a second reading head. The second sliding plate is disposed above the second base and is driven by the second motor to move along the second base. The second grating ruler is disposed along the second base, and the second reading head is disposed on the second sliding plate to determine the position coordinates of the second sliding plate. Both ends of the gantry frame are provided with fixing plates. The fixing plates have inward grooves along the axis of the gantry frame. The protrusions on both sides of the grooves are connected by spring plates. The first crossbeam and the second crossbeam are respectively connected to the spring plates by fixing blocks to achieve flexible connection with the gantry frame. An adjustment mechanism is also provided, which is disposed on the first sliding plate and / or the second sliding plate. The adjustment mechanism includes an adjustment base and an adjustment bolt. The adjustment bolt is threaded to the adjustment base and passes through the adjustment base to abut against the fixed block. By rotating the adjustment bolt, the fixed block and the gantry frame are pushed to adjust the vertical relationship between the gantry frame and the first crossbeam and the second crossbeam. The gantry includes a third base, a third sliding plate, and a third motor. The third sliding plate is disposed above the third base, and the third motor drives the third sliding plate to move along the third base. The synchronization error compensation method for the gantry mechanism includes the following steps: S1: A camera is installed on the third sliding plate of the gantry, and a calibration plate is placed in the working area of ​​the gantry mechanism; S2: Control the first motor and the second motor to move to the working zero position; control the gantry mechanism to move the center of the camera to the first calibration point of the calibration plate; use the third motor to move the camera along the gantry to the second calibration point of the calibration plate; adjust the calibration plate to ensure that the spatial position of the first calibration point remains unchanged, so that the center of the camera coincides with the second calibration point; S3: Select a third calibration point on the calibration plate. The line between the third calibration point and the first calibration point is perpendicular to the line between the second calibration point and the first calibration point. Calculate the reference distance Xn between the first calibration point and the third calibration point. Move the center of the camera to the first calibration point of the calibration plate, control the first motor and the second motor to move a reference distance Xn, and measure the error distance ΔXn between the center movement of the camera and the third calibration point; S4: Control the first motor or the second motor as the active motor and the second motor or the first motor as the driven motor; use the first motor or the second motor as a reference to perform linear compensation on the second motor or the first motor, with a unit distance compensation value of ΔXn / Xn.

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