High-precision positioning robot series-parallel structure and application thereof
Through the hybrid structure of high-precision positioning robots, combined with coarse adjustment, fine adjustment and error compensation mechanisms, the problems of insufficient dynamic accuracy and poor adaptability of existing positioning robots in radiotherapy are solved. Large-stroke positioning and high-precision adjustment are achieved, which can adapt to patients of different body sizes and complex treatment positions, and improve the positioning accuracy and flexibility of radiotherapy.
Patent Information
- Application Number
- CN202510826910.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-19
- Publication Date
- 2025-09-19
AI Technical Summary
Existing positioning robots have problems with insufficient dynamic accuracy and poor adaptability in radiotherapy, especially the large error accumulation of the series structure and the small motion space of the parallel structure, which make it difficult to meet the needs of high-precision positioning and large-range movement.
A high-precision positioning robot hybrid structure is adopted, including a coarse adjustment mechanism, a fine adjustment mechanism and an end rotation mechanism, combined with an error compensation mechanism to achieve long-stroke positioning, fine posture compensation and real-time error correction. The positioning accuracy and adaptability are improved through the combination of X-axis and Y-axis linear guide slides, 3-RPS parallel structure and laser tracker.
It achieves high-precision positioning for large-stroke movements, adapts to patients of different sizes and complex treatment positions, corrects errors in real time, and improves the positioning accuracy and flexibility of radiotherapy.
Smart Images
Figure CN120661853A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of medical robots, and in particular relates to a high-precision positioning robot hybrid structure and its application. Background Art
[0002] Radiotherapy is a localized treatment method that uses radiation to treat tumors. To continuously improve the precision and accuracy of each step in radiotherapy, radiotherapy equipment has higher requirements for precise positioning, precise delivery, and precise irradiation. Medical treatment couches play a crucial role in this precise positioning. Conventional treatment couches are used to support and secure patients; however, the positioning accuracy requirements for radiotherapy couches are becoming increasingly stringent. Furthermore, with the application of IGRT and ART technologies, internal target position deviations can be detected and corrected online. A treatment couch with high positioning accuracy and strong reliability will significantly improve patient fixation and positioning, ultimately achieving the goal of precise radiotherapy.
[0003] Positioning robots in the existing technology generally adopt a single series or parallel structure, which has problems such as insufficient dynamic accuracy and poor adaptability. After searching, the content published in CN 117773905 A is not easy to ensure the adjustment accuracy by positioning the robotic arm to adapt to the spatial operation requirements of different surgical procedures and the operating habits of different medical staff.
[0004] While serial positioning robots offer a large range of motion, their structural characteristics result in significant error accumulation and low dynamic accuracy. Parallel positioning robots, while offering high stiffness and precision, suffer from a smaller range of motion and poor adaptability. Therefore, designing a positioning robot structure that can achieve a large range of motion while ensuring high-precision positioning and strong adaptability remains a pressing technical challenge. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a high-precision positioning robot hybrid structure and its application.
[0006] The high-precision positioning robot hybrid structure of the present invention adopts the following technical solutions: A high-precision positioning robot hybrid structure includes a base plate and a coarse adjustment mechanism placed on the base plate. A fine adjustment mechanism based on a 3-RPS parallel structure is provided on the Y-axis linear guide slide of the coarse adjustment mechanism. An end rotation mechanism is provided on the moving platform of the fine adjustment mechanism. An error compensation mechanism is provided on the base plate on one side of the coarse adjustment mechanism.
[0007] The beneficial effects of the present invention adopting the above technical solution are: the coarse adjustment mechanism realizes large-stroke positioning, meeting the requirements of radiotherapy for large-range spatial coverage; the parallel fine adjustment mechanism adopts a 3-RPS parallel structure, which has the characteristics of high rigidity and low error accumulation, realizes high-precision adjustment, and ensures the positioning accuracy of radiotherapy; the terminal rotation mechanism realizes fine posture compensation of the bed board, improves the flexibility of the system, and can adapt to patients of different body shapes and complex treatment positions; the error compensation mechanism collects calibration point data in real time, and corrects the errors in the mechanism movement by fitting the geometric error, realizing real-time correction of the dynamic error of the hybrid mechanism treatment bed and improving positioning accuracy.
[0008] The present invention adopts the following preferred embodiment: Preferred option: The X-axis linear guide in the coarse adjustment mechanism is mounted on the base plate, the X-axis linear guide is mounted on the X-axis linear guide slide, the Y-axis linear guide is mounted on the X-axis linear guide slide, the Y-axis linear guide is mounted on the Y-axis linear guide slide, and the fixed platform in the fine adjustment mechanism is mounted on the Y-axis linear guide slide.
[0009] The fine adjustment mechanism includes a fixed platform, a movable platform, and three identical branched chain structures connecting the fixed platform and the movable platform. The branched chain structures are composed of a rotating pair, a first moving pair, and a spherical pair.
[0010] The rotary joint in the terminal rotation mechanism is placed on the moving platform, and the other end of the rotary joint is connected to the bed board.
[0011] The laser tracker in the error compensation mechanism is placed above the second moving pair, the bottom end of the second moving pair is connected to the base plate, and the upper end of the second moving pair is connected to the laser tracker.
[0012] An X-axis drive motor is installed on the X-axis linear guide rail, the X-axis drive motor is connected to the X-axis lead screw, the X-axis lead screw is connected to the first slider on the lower end surface of the X-axis linear slide, and the first slider is connected to the X-axis linear slide.
[0013] The Y-axis linear guide is equipped with a Y-axis drive motor, the Y-axis drive motor is connected to the Y-axis lead screw, the Y-axis lead screw is connected to the second slider on the lower end surface of the Y-axis linear slide, and the second slider is connected to the Y-axis linear slide.
[0014] The plumb line where the axis of the second moving pair is located is perpendicular to and intersects with the perpendicular midline of the long side of the base plate.
[0015] The revolute joint is a joint that rotates around the Z axis.
[0016] Application scheme of the high-precision positioning robot hybrid structure of the present invention: An application of the high-precision positioning robot hybrid structure is used in a radiotherapy bed. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a structural schematic diagram of the present invention.
[0018] Figure 2 This is the main view of the coarse adjustment mechanism.
[0019] Figure 3 yes Figure 1 A-direction view in.
[0020] Figure 4 yes Figure 3 GG cross-sectional view in.
[0021] Figure 5 It is the main view of the fine adjustment mechanism.
[0022] Figure 6 It is a three-dimensional diagram of the terminal rotation mechanism. DETAILED DESCRIPTION
[0023] The specific structure and application of the present invention are described in detail below with reference to the accompanying drawings and embodiments: A high-precision positioning robot hybrid structure, see the attached Figure 1-6 The specific structure described in the figure includes: a base plate 1, an X-axis drive motor 2, an X-axis lead screw 3, an X-axis linear guide 4, an X-axis linear guide slide 5, a Y-axis drive motor 6, a Y-axis drive lead screw 7, a Y-axis linear guide 8, a Y-axis linear guide slide 9, a fixed platform 10, a moving platform 11, a rotating pair 12, a first moving pair 13, a spherical pair 14, a rotary joint 15, a bed plate 16, a second moving pair 17, and a laser tracker 18.
[0024] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the following detailed description of the specific embodiments of the present invention is given in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention.
[0025] However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0026] In the description of the present invention, it should be understood that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 any limitation on the claims of the present invention.
[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, technical features with the same name may explicitly or implicitly include at least one of the features.
[0028] The technical features mentioned in this embodiment include, but are not limited to, for example: the laser tracker 18 can be a commercially available product.
[0029] In this embodiment, a high-precision positioning robot hybrid structure includes a base plate 1, a coarse adjustment mechanism placed on the base plate 1, a fine adjustment mechanism based on a 3-RPS parallel structure is provided on the Y-axis linear guide slide 9 in the coarse adjustment mechanism, an end rotation mechanism is provided on the moving platform 11 in the fine adjustment mechanism, and an error compensation mechanism is provided on the base plate 1 on one side of the coarse adjustment mechanism.
[0030] The bottom plate 1 is a rectangular plate structure. Figure 1 As indicated in the figure, the left-right length direction of the bottom plate 1 is the X-axis direction, the front-back width direction of the bottom plate is the Y-axis direction, and the direction perpendicular to the upper and lower surfaces of the bottom plate 1 is the Z-axis direction.
[0031] An X-axis linear guide 4 is installed along the left and right length of the upper surface of the base plate 1. An X-axis linear guide slide 5 is installed above the X-axis linear guide 4. The X-axis linear guide slide 5 can move left and right along the X-axis linear guide 4. An X-axis drive motor 2 is installed at one end of the X-axis linear guide 4. The output shaft of the X-axis drive motor 2 is connected to the X-axis drive screw 3. The X-axis drive motor 2 is connected to the X-axis linear guide slide 5 through a screw transmission mechanism.
[0032] When the X-axis drive motor 2 rotates, it drives the X-axis drive screw 3 to rotate, thereby driving the X-axis linear guide slide 5 to move left and right along the X-axis linear guide 4 through the X-axis screw transmission mechanism where the X-axis drive screw 3 is located (the X-axis screw transmission mechanism includes not only the X-axis drive screw 3, but also a first slider that cooperates with the X-axis drive screw. The first slider is not shown in the figure. The first slider is installed below the X-axis linear guide slide 5), thereby realizing movement in the X-axis direction.
[0033] A Y-axis linear guide 8 is installed on the upper surface of the X-axis linear guide platform 5 along the width of the base plate 1. A Y-axis linear guide platform 9 is installed above the Y-axis linear guide 8. The Y-axis linear guide platform 9 can move back and forth along the Y-axis linear guide 8. A Y-axis drive motor 6 is installed at one end of the Y-axis linear guide 8. The output shaft of the Y-axis drive motor 6 is connected to the Y-axis drive screw 7. The Y-axis drive motor 6 is connected to the Y-axis linear guide platform 9 through the Y-axis screw transmission mechanism in which the Y-axis drive screw 7 is located (the Y-axis screw transmission mechanism includes not only the Y-axis drive screw 7 but also a second slider that cooperates with the Y-axis drive screw 7 (the second slider is not shown in the figure and is mounted below the Y-axis linear guide platform 9).
[0034] The length of the X-axis linear guide 4 is equal to the length of the Y-axis linear guide 8; the length of the X-axis linear guide slide 5 is equal to the length of the Y-axis linear guide slide 9; in this embodiment, the X-axis linear guide 4 and the X-axis linear guide slide 5 are respectively square structures, and the Y-axis linear guide 8 and the Y-axis linear guide slide 9 are also respectively square structures.
[0035] When the Y-axis drive motor 6 rotates, it drives the Y-axis drive screw 7 to rotate, thereby driving the Y-axis linear guide slide 9 to move back and forth along the Y-axis linear guide 8 through the Y-axis screw transmission mechanism, realizing movement in the Y-axis direction; the X-axis linear guide 4 and the Y-axis linear guide 8 are superimposed in series to form a series coarse adjustment mechanism, realizing long-stroke positioning.
[0036] A fixed platform 10 is fixed above the Y-axis linear guide slide 9. This platform 10 serves as the base of the 3-PRS parallel structure. The 3-PRS parallel structure also includes a moving platform 11 and three identical branched chains connecting the fixed and moving platforms 10. Each branched chain consists of a revolute pair 12, a translatory pair 13, and a spherical pair 14. The three branches are evenly spaced at 120 degrees between the fixed and moving platforms 10 and 11. The revolute pair 12 is connected to the fixed platform 10, and the spherical pair 14 is connected to the moving platform 11. The first translatory pair 13 is located between the revolute pair 12 and the spherical pair 14. By controlling the extension and contraction of the moving pair 13 in the three-branch structure, the dynamic platform 11 can be driven to perform three-degree-of-freedom movement in space: rising and falling movement along the Z axis; rotational movement around the X axis, such as tilting the bed board 16 forward and backward; and rotational movement around the Y axis, such as tilting the bed board 16 left and right.
[0037] A terminal rotation mechanism is located above the moving platform 11. This mechanism includes a rotary joint 15, which rotates about a vertical axis (the Z axis). One end of the rotary joint 15 is fixedly connected to the moving platform 11, and the other end is fixedly connected to the bed plate 16. Rotation of the rotary joint 15 drives the bed plate 16 to rotate continuously 360 degrees around the vertical axis, achieving precise posture compensation and ensuring accurate alignment of the treatment device's isocenter with the tumor target.
[0038] The laser tracker 18 in the error compensation mechanism is positioned above the second movable joint 17. The bottom end of the second movable joint 17 is fixedly connected to the base plate 16, and the top end of the second movable joint 17 is fixedly connected to the laser tracker 18. The plumb line of the axis of the second movable joint 17 is perpendicular to the mid-perpendicular line of the long side of the base plate 16, and the laser tracker 18 is positioned in the preferred manner in this embodiment. The elongated base of the second movable joint 17 is connected to the base plate 16.
[0039] The laser tracker 18 is used to collect calibration point data in real time and correct errors in the mechanism movement by fitting geometric error parameters; its measurement accuracy depends on the alignment accuracy of the laser beam and the target point, so the position setting must meet the requirements of "full coverage of the measurement range" and "reduction of measurement blind spots".
[0040] The error compensation mechanism of this embodiment includes a laser tracker 18 and a BP neural network module. The laser tracker 18 is used to collect calibration point data, fit geometric error parameters, and correct errors such as the length deviation of the second movable pair 17 (the piston rod of the electric cylinder or hydraulic cylinder is responsible for transmitting motion and bearing load, and its length deviation requires error compensation correction) and the joint clearance of the rotary joint 15 (the motion error caused by the clearance of the rotary joint itself can be compensated in real time). The BP neural network module is used to learn thermal deformation and load nonlinear errors to achieve real-time correction of dynamic errors and improve positioning accuracy. The BP neural network module includes a multimodal perception system, which includes an NDI optical tracking system and a 4D-CBCT imaging system. The multimodal perception system is used to perceive the patient's physiological movement information in real time and provide data support for dynamic positioning error compensation. By providing the error compensation device and multimodal perception system, the positioning robot can effectively compensate for errors during movement, perceive the patient's physiological movement in real time, achieve dynamic positioning error compensation, and improve the adaptability and reliability of the positioning robot in complex clinical scenarios.
[0041] When used in radiotherapy, the working process and principle are as follows: During radiotherapy, the patient lies on the bed 16; when coarse positioning with a large stroke is required, the X-axis drive motor 2 and the Y-axis drive motor 6 are controlled to drive the X-axis linear guide slide 5 and the Y-axis linear guide slide 9 to move, thereby adjusting the bed 16 in the X-axis and Y-axis directions and moving the bed 16 to the vicinity of the target area.
[0042] When high-precision adjustment is required, the moving pairs 13 of the three branched structures in the 3-RPS parallel structure are controlled to extend and retract, driving the dynamic platform 11 to move in three degrees of freedom in space, thereby driving the bed board 16 to make precise position and posture adjustments, so that the bed board 16 reaches the precise treatment position.
[0043] When fine posture compensation is required, the rotation joint 15 of the terminal rotation mechanism is controlled to rotate, driving the bed board 16 to rotate around the vertical axis (Z axis), and the posture of the bed board 16 is finely adjusted to adapt to the patient's position changes or the adjustment requirements of the radiation beam angle.
[0044] When real-time error compensation is required, the movement of the movable pair 17 is controlled to drive the laser tracker 18 to rise and fall along the vertical direction of the Z axis. After the laser tracker 18 reaches the expected position, it collects calibration point data in real time and fits the geometric error parameters to correct the errors in the mechanism movement.
[0045] The above description is merely a preferred embodiment of the present invention and does not limit the present invention in any way. Any person skilled in the art may make equivalent changes or modifications based on the above disclosure without departing from the scope of the present invention, and such changes or modifications shall be within the scope of protection of the present invention.
Claims
1. A high-precision positioning robot hybrid structure, comprising a base plate and a coarse adjustment mechanism placed on the base plate, characterized in that: A fine adjustment mechanism based on a 3-RPS parallel structure is provided on the Y-axis linear guide slide in the coarse adjustment mechanism, an end rotation mechanism is provided on the movable platform in the fine adjustment mechanism, and an error compensation mechanism is provided on the bottom plate on one side of the coarse adjustment mechanism.
2. The high-precision positioning robot hybrid structure according to claim 1 is characterized in that: The X-axis linear guide in the coarse adjustment mechanism is mounted on the base plate, the X-axis linear guide is mounted on the X-axis linear guide slide, the Y-axis linear guide is mounted on the X-axis linear guide slide, the Y-axis linear guide is mounted on the Y-axis linear guide slide, and the fixed platform in the fine adjustment mechanism is mounted on the Y-axis linear guide slide.
3. The high-precision positioning robot hybrid structure according to claim 1 is characterized in that: The fine adjustment mechanism includes a fixed platform, a movable platform, and three identical branched chain structures connecting the fixed platform and the movable platform. The branched chain structures are composed of a rotating pair, a first moving pair, and a spherical pair.
4. The high-precision positioning robot hybrid structure according to claim 1 is characterized in that: The rotary joint in the terminal rotation mechanism is placed on the moving platform, and the other end of the rotary joint is connected to the bed board.
5. The high-precision positioning robot hybrid structure according to claim 1 is characterized in that: The laser tracker in the error compensation mechanism is placed above the second moving pair, the bottom end of the second moving pair is connected to the base plate, and the upper end of the second moving pair is connected to the laser tracker.
6. The high-precision positioning robot hybrid structure according to claim 2, characterized in that: An X-axis drive motor is installed on the X-axis linear guide rail, the X-axis drive motor is connected to the X-axis lead screw, the X-axis lead screw is connected to the first slider on the lower end surface of the X-axis linear slide, and the first slider is connected to the X-axis linear slide.
7. The high-precision positioning robot hybrid structure according to claim 1 or 2, characterized in that: The Y-axis linear guide is equipped with a Y-axis drive motor, the Y-axis drive motor is connected to the Y-axis lead screw, the Y-axis lead screw is connected to the second slider on the lower end surface of the Y-axis linear slide, and the second slider is connected to the Y-axis linear slide.
8. The high-precision positioning robot hybrid structure according to claim 5, characterized in that: The plumb line where the axis of the second moving pair is located is perpendicular to and intersects with the perpendicular midline of the long side of the base plate.
9. The high-precision positioning robot hybrid structure according to claim 4, characterized in that: The revolute joint is a joint that rotates around the Z axis.
10. An application of a high-precision positioning robot hybrid structure according to any one of claims 1 to 9, characterized in that: Application in radiotherapy beds.