A multi-degree of freedom digestive tract surgical robot system

Abstract

This invention proposes a multi-degree-of-freedom gastrointestinal surgical robot system, belonging to the field of medical robot technology. It includes a platform with a pair of guide rails on its end face; a main arm drive device mounted on the platform, its output end connected to one end of the main arm to provide power to the main arm, which is hollow inside; a deployment mechanism mounted on the other end of the main arm away from the platform; two sub-arm drive devices respectively mounted on the platform and slidably connected to the guide rails; the output ends of the two sub-arm drive devices pass through the main arm and extend into the deployment mechanism to provide power to the deployment mechanism; the deployment mechanism includes a snake-bone tube and a force-sensitive elastomer clamping unit. The snake-bone tube includes several sequentially arranged rotary joints, adjacent rotary joints are hinged together, the interior of the first rotary joint communicates with a channel inside the main arm, and the last rotary joint is connected to the force-sensitive elastomer clamping unit. Clamping force and three-dimensional force sensing are achieved through inverse kinematics calculation.

Description

Technical Field

[0001] This invention relates to the field of medical robotics, and more particularly to a multi-degree-of-freedom gastrointestinal surgical robot system. Background Technology

[0002] Gastrointestinal tumors are a prevalent disease in my country, making early diagnosis and treatment crucial. For early-stage gastrointestinal cancers, endoscopic submucosal dissection (ESD) has become the standard treatment, offering advantages such as being non-invasive, preserving anatomical structures, minimally invasive, allowing for rapid recovery, and being cost-effective. However, ESD demands highly skilled operators, has a long learning curve, and carries a relatively high risk of intraoperative bleeding and perforation. To improve surgical field exposure and stabilize tension, while reducing complications and the learning curve, endoscopic surgical robots have emerged. By providing stable traction, precise cutting, and suturing capabilities within narrow cavities, these robots promote the safer implementation of ESD in a wider range of populations and institutions.

[0003] Traditional endoscopic submucosal dissection (ESD) often relies on "assisted traction" strategies such as gravity traction, rubber clips / elastic coils, and magnetic traction. These strategies suffer from limitations such as restricted traction direction control, discontinuous tension adjustment, and some invasiveness, making it difficult to stably form a "operation triangle" similar to that of a laparoscopy, especially in deep or curved areas. On the other hand, systems like the da Vinci, as general-purpose platforms, are widely used in many surgical fields. However, their size and rigidity are not tailored to narrow natural cavities and the long, winding "oral-esophageal-stomach-colon" pathway, creating inherent tensions in adaptability to deep, narrow surgical fields, instrument access, and flexible manipulation. Continuum robots offer greater compliance and dexterity within narrow, curved digestive tracts, enabling stable traction, precise incision, and suturing in confined spaces. Common configurations include concentric tubes, origami-like designs, and spring-like designs, but challenges remain regarding lateral / axial stiffness, size, and controllability. In recent years, miniature continuous flexible robotic arms for endoscopic submucosal dissection (ESD) have become an important direction: for example, a scheme with a diameter of about 3 mm that can achieve precise master-slave control of 4 degrees of freedom can provide stable lifting through the movement of the robotic arm, making the operation closer to the surgeon's intuition, and is expected to shorten the operation time, reduce complications and expand the indications.

[0004] Therefore, it is essential to provide a multi-degree-of-freedom gastrointestinal surgical robot system that, through the deep integration of multi-degree-of-freedom mechanical structure design and fiber optic force sensing technology, can monitor the interaction force between instruments and tissues in real time, significantly improving the accuracy and safety of gastrointestinal surgery. Summary of the Invention

[0005] In view of this, the present invention proposes a rigid-flexible coupling robot body configuration based on discrete ball joints, realizes the embedded fabrication and integrated integration of fiber optic interactive force sensing units on actuators, and a multi-degree-of-freedom gastrointestinal surgical robot system for decoupling the fiber optic sensing of the rigid-flexible coupling surgical actuator interactive force.

[0006] This invention provides a multi-degree-of-freedom gastrointestinal surgical robot system, comprising: The platform has a pair of guide rails on its end face; The main boom is located on one side of the platform; The main boom drive unit is set on the platform, and its output end is connected to one end of the main boom to provide power to the main boom. The main boom is hollow inside. The deployment mechanism is located at the other end of the main arm, away from the platform. The two sub-arms are each mounted on the platform and slidably connected to the guide rails. The two sub-arms move linearly along the guide rails. The output end of the two sub-arms passes through the main arm and extends into the deployment mechanism to provide power to the deployment mechanism. The unfolding mechanism includes at least one snake-bone tube and a force-sensitive elastomer clamping unit. The snake-bone tube includes several sequentially arranged rotary joints. Adjacent rotary joints are hinged together. The interior of the rotary joint at the first end is connected to the channel inside the main arm. The rotary joint at the last end is connected to the force-sensitive elastomer clamping unit. Through inverse kinematics calculation, clamping force and three-dimensional force sensing are realized.

[0007] Based on the above technical solutions, preferably, the main boom drive device includes a first motor mounting base, a plurality of first motors, a plurality of first couplings, a motor support, a rear mounting plate, a plurality of support columns, a plurality of ball screws, a bearing seat, a front mounting plate, a nut extension piece, a main boom bracket, an optical shaft, and a base; the base is fixedly mounted relative to the platform; the first motor mounting base, the rear mounting plate, and the front mounting plate are parallel to each other and spaced apart; the plurality of support columns are sequentially mounted through the first motor mounting base, the rear mounting plate, and the front mounting plate, and one end of each support column passes through the front mounting plate and is fixedly connected to the main boom bracket; the interior of the main boom bracket is connected to the interior of the main boom; the outlines of the first motor mounting base, the rear mounting plate, and the front mounting plate are all annular, and their central axes are coaxial; the plurality of support columns are evenly spaced circumferentially relative to the central axis of the first motor mounting base; the plurality of first motors are mounted on the end face of the first motor mounting base away from the rear mounting plate; the two ends of the plurality of ball screws... The main arm is rotatably connected to the front and rear fixed plates via bearing seats. A nut is mounted on the ball screw, forming a helical pair with the ball screw. A nut extension is also fixedly mounted on the nut. A light shaft is positioned between the front and rear fixed plates. One end of the nut extension extends towards the light shaft and is slidably connected to it. Several first motors are fixedly mounted on first motor mounting seats, with their output shafts passing through these seats and connected to the ball screws via first couplings. The first motors output torque, driving the nuts to move linearly through the ball screws. The main arm also contains a main arm drive guide wire and a main arm push rod. These are fixedly connected to different nut extensions, and are also connected to the flexible section of the main arm. The main arm drive guide wire adjusts the bending of the flexible section along a preset direction, and the main arm push rod drives the extension and retraction of the flexible section.

[0008] Preferably, each of the two sub-arm drive units includes a sub-arm drive unit, a quick-release frame, a shaft fixing plate, a second motor, a motor fixing plate, a fixed housing, a driver assembly plate, a spring lever, a sub-arm motor mounting base, and a shaft unit. The fixed housing is hollow inside and has an opening on one side. The motor fixing plate, the shaft fixing plate, and the sub-arm drive unit are sequentially spaced along the normal direction of the opening of the fixed housing. The motor fixing plate and the shaft fixing plate are both fixedly connected to the fixed housing, and the quick-release frame is hinged to the shaft fixing plate. The second motor is fixedly mounted on the motor fixing plate. The output shaft of the second motor is connected to one end of a second coupling, and the other end of the second coupling passes through the shaft fixing plate and connects to the shaft unit. The shaft unit is embedded in the sub-arm drive unit. The driver assembly plate is fastened to the shaft fixing plate and is used to install the second motor driver. The sub-arm drive unit is provided with a protrusion, and the shaft unit is correspondingly provided with... The main arm has grooves, and the protrusions correspond to and cooperate with the grooves. One end of the spring lever is connected to the sub-arm drive unit via a pin to form a rotating joint. The other end of the spring lever has a hook-like structure, which is used to abut against the corresponding hook groove structure preset on the rotating shaft fixing plate, constraining the relative position of the sub-arm drive unit and the rotating shaft fixing plate. The sub-arm motor fixing seat and the motor fixing plate are fastened together by bolts. Several sub-arm drive guide wires are also provided inside the main arm. One end of the sub-arm drive guide wires extends into the unfolding mechanism and is fixedly connected to different positions of the unfolding mechanism. The other end of the sub-arm drive guide wires is connected to the sub-arm drive unit, which is used to adjust the posture of the unfolding mechanism. The fixed shell is also connected to the guide rail to form a sliding joint. The fixed shell is also connected to the push motor, which drives the fixed shell to move linearly along the guide rail. The second motor is used to wind or unwind several sub-arm drive guide wires to adjust the posture of the unfolding mechanism.

[0009] A further preferred embodiment of the sub-arm drive unit includes a reel cover, a reel base plate, a guide wheel, and a reel module. The reel cover and the reel base plate are directly opposite each other and fixedly installed, forming a gap between them. The guide wheel is located within the gap area and is rotatably connected to the reel base plate. The reel module is located between the reel cover and the reel base plate. Corresponding through mounting holes are provided on the reel cover and the reel base plate. The reel module passes through the mounting holes and extends toward the direction of the rotating shaft fixing plate. The spool module includes a shaft, two bearings, a spring, a winding wheel, and a stop. The two bearings are spaced apart along the axial extension direction of the shaft and are correspondingly embedded in the mounting holes of the spool cover and the spool base plate. The winding wheel is fixedly mounted on the shaft. A spring is sleeved on the shaft between the winding wheel and the spool cover, and a stop is sleeved on the shaft between the winding wheel and the spool base plate. The spring is used to absorb the instantaneous impact of the winding wheel and maintain the stability of the two bearings.

[0010] Further preferably, the deployment mechanism further includes a deployment push rod, two deployment connecting rods, a hollow end, a deployment channel, a curved endoscope, and a force sensing unit; the end is hollow inside and is used to connect to the end of the main arm away from the main arm drive device, and the end has an endoscope hole; the deployment push rod includes a connector and a rod body, the rod body is inserted into the end and fixedly connected to the end, the connector is fixedly connected to one end of each of the two deployment connecting rods, and the other ends of the two deployment connecting rods are connected to the deployment channel; the deployment channel has a channel body, and the snake-bone tube is connected to the channel body by metal glue, thereby enabling the integrated channel and the channel body to communicate with each other; the curved endoscope is fixed in the endoscope hole of the end with metal glue; the force-sensitive elastomer clamping unit is connected to the end of the snake-bone tube away from the end through metal glue, and the force-sensitive elastomer clamping unit includes a fixed clamp head, a movable clamp head, a rotating pin, and a clamp bracket, one end of the clamp bracket is provided with an outwardly extending fixed clamp head, the rotating pin is installed on the fixed clamp head and rotatably connected to the fixed clamp head, and the movable clamp head is fixedly installed on the rotating pin. On the moving pin, a force sensing unit is installed at the other end of the clamp support. The force sensing unit includes four hollow beams and six surface-metallized fiber Bragg gratings. The four hollow beams are inclined relative to the central axis of the clamp linkage. The four surface-metallized fiber Bragg gratings are installed one-to-one inside the hollow beams and are fixedly tensioned at both ends, forming a fiber Bragg grating array. When the force-sensitive elastomer clamping unit is subjected to an external three-dimensional force, the force-sensitive elastomer clamping unit amplifies the strain corresponding to the three-dimensional force and transmits it to the fiber Bragg grating array, obtains the wavelength change of the fiber Bragg grating array and decouples it, realizing real-time detection and analysis of the three-dimensional force. The other two surface-metallized fiber Bragg gratings are used to measure the clamping force of the force-sensitive elastomer clamping unit and realize temperature compensation decoupling. One sub-arm drive guide wire also passes through the snake bone tube and is fixedly connected to the rotating pin, which is used to drive the rotating pin to rotate or reset, thereby opening or resetting the moving clamp head. The snake bone tube is connected to the four sub-arm drive guide wires to realize rotation in two directions.

[0011] In a further preferred embodiment, the snake-bone tube includes a hollow, adjacently arranged head rotation joint, several intermediate rotation joints, and a tail rotation joint. The head rotation joint has symmetrically arranged slots extending away from the tail end. Each intermediate rotation joint has symmetrically arranged arc-shaped protrusions at one end, extending towards the tail end. The other end of each intermediate rotation joint also has symmetrically arranged outwardly extending slots, which are fitted with the arc-shaped protrusions with a clearance fit. The slots or arc-shaped protrusions of adjacent rotation joints are aligned face-to-face. Two... The end slot is spaced 90° from the arc-shaped protrusion; each rotary joint is equipped with a wiring ring, which has four through-holes for the sub-arm drive wires and two fiber optic holes. The four sub-arm drive wire holes are evenly distributed relative to the central axis of the wiring ring and are fixedly connected to the end rotary joint; the two fiber optic holes are used to form channels for two surface-metallized fiber optic gratings for measuring the clamping force of the force-sensitive elastomer clamping unit; in the snake tube, any two non-adjacent sub-arm drive wires serve as pitch adjustment wires and offset adjustment wires, respectively.

[0012] In a further preferred embodiment, the curved endoscope includes a camera and an arc-shaped connecting part, with the camera embedded at one end of the arc-shaped connecting part and the other end of the arc-shaped connecting part embedded in the endoscope aperture at the end.

[0013] More preferably, the inverse kinematics calculation includes the following: establishing a geometric and kinematic model; simplifying the deployment mechanism using a piecewise constant curvature model; assuming that each rotary joint of the deployment mechanism maintains constant curvature during movement; establishing a coordinate system at each rotary joint of the snake-bone tube; and establishing a base coordinate system at the curved endoscope; deriving the transformation matrix; and deriving the first transformation matrix based on geometric relationships. i The coordinate system of the rotational joint is to i +1 homogeneous transformation matrix of the coordinate system of the rotation joints i ∈ N , N Given the total number of rotary joints, the global transformation matrix from the base coordinate system to the force-sensitive elastic body clamping unit is further obtained. A kinematic model is established using the global exponential product method based on spinor theory, representing the motion of each rotary joint as an exponential transformation along a helical axis. The pose of the end rotary joint of the snake tube is obtained by multiplying the transformations of all rotary joints. Inverse kinematics is solved, and based on the constant curvature assumption and geometric relationships, the bending motion of the snake tube is decomposed into the superposition of pitch and yaw rotary joints. The required rotation angle of each pitch and yaw rotary joint is calculated, and a mathematical relationship is established between the rotation angle and the length change of the four sub-arm drive guidewires of the snake tube, realizing the correlation between the operation command and the actual action of the deployment mechanism.

[0014] In a further preferred embodiment, the realization of clamping force and three-dimensional force sensing includes the following: based on the structure of the force-sensitive elastomer clamping unit, four hollow beams and four corresponding surface-metallized fiber optic gratings are used to form an integrated four-channel fiber optic force sensor; a mathematical relationship is established between the external force and the microscopic deformation of the hollow beam where each fiber optic grating is located; according to the principle of fiber optic gratings, a relationship between wavelength drift and fiber optic grating strain is established, and the real-time wavelength drift is obtained; a mapping relationship between wavelength drift and three-dimensional force is established, and finally, the calculated three-dimensional force and clamping force are output.

[0015] Based on the above technical solutions, preferably, it also includes a passive section, which is located between the main drive device of the two sub-arms and the main arm, and the passive section forms a space for accommodating several sub-arm drive guide wires.

[0016] The multi-degree-of-freedom gastrointestinal surgical robot system provided by this invention has the following advantages compared with the prior art: 1. Through the deep integration of multi-degree-of-freedom mechanical structure design and fiber optic force sensing technology, the precision and safety of gastrointestinal surgery are significantly improved. A collaborative control scheme employing main arm drive, sub-arm drive, guide rails, and deployment mechanism enables the flexible operating arm to achieve precise multi-angle guidance and stable traction within the narrow and winding digestive tract. The snake-bone tube is composed of modular connecting units connected in series, and through guidewire control, it can flexibly bend in any direction in space based on a segmented constant curvature model. This rigid-flexible coupling structure effectively overcomes the limitations of traction direction and the difficulty in forming an operating triangle in traditional endoscopic surgery, providing surgeons with a more intuitive master-slave control experience.

[0017] 2. A major breakthrough has been achieved in force sensing, with real-time monitoring of the interaction force between the instrument and tissue via an embedded fiber Bragg grating sensor. The clamp integrates a metallized fiber Bragg grating array. When external force is applied to the force-sensitive elastic body, the three-dimensional force state and clamping force magnitude can be accurately analyzed by decoupling the fiber wavelength drift signal. This closed-loop force feedback mechanism can dynamically warn of the risk of excessive force, avoiding tissue perforation or bleeding, and significantly reducing the incidence of ESD complications. The fiber optic cable is integrated with the actuator using laser welding technology, ensuring the stability and miniaturization of the sensing unit.

[0018] 3. Modular design enhances surgical adaptability. The snake-bone tube end can be quickly replaced with various actuators such as clamps, scissors, and curettes to meet diverse surgical needs such as cutting, suturing, and suction. The guide rail mechanism can connect with commercial collaborative robotic arms to achieve overall preoperative posture adjustment, improving the system's compatibility with existing medical equipment. By mapping the master hand displacement to the operator arm bending angle through inverse kinematics algorithms, human-computer interaction efficiency is further optimized, shortening the surgeon's learning curve.

[0019] 4. The digestive endoscopic surgical robot proposed in this invention, through mechatronics innovation, constructs a digestive tract surgical platform integrating precise operation, real-time force feedback, and adaptability to confined spaces. Its technical effects are directly reflected in improved surgical safety, reduced operational difficulty, and expanded indications for minimally invasive treatment. It provides a domestically developed solution for the precise diagnosis and treatment of early-stage digestive tract cancer, possessing significant clinical value and industrialization prospects. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is an overall structural diagram of a multi-degree-of-freedom gastrointestinal surgical robot system according to the present invention; Figure 2 This is a structural diagram of the main arm drive device of a multi-degree-of-freedom digestive tract surgical robot system according to the present invention; Figure 3 This is a schematic diagram of the structure of the first motor mounting base and bearing housing of a multi-degree-of-freedom digestive tract surgical robot system according to the present invention; Figure 4 This is a structural diagram of the subarm drive device of a multi-degree-of-freedom digestive tract surgical robot system according to the present invention; Figure 5 This is a structural diagram of the second motor portion of the subarm drive unit of a multi-degree-of-freedom digestive tract surgical robot system according to the present invention; Figure 6 This is a schematic diagram of the sub-arm drive unit of a multi-degree-of-freedom gastrointestinal surgical robot system according to the present invention; Figure 7 This is a schematic diagram of the thread wheel module of a multi-degree-of-freedom gastrointestinal surgical robot system of the present invention; Figure 8 This is a schematic diagram of the deployment mechanism of a multi-degree-of-freedom digestive tract surgical robot system according to the present invention; Figure 9 This is a schematic diagram of the deployment channel of a multi-degree-of-freedom digestive tract surgical robot system according to the present invention; Figure 10 This is a schematic diagram of the deployment push rod of a multi-degree-of-freedom digestive tract surgical robot system according to the present invention; Figure 11 This is a schematic diagram of the snake-bone tube structure of a multi-degree-of-freedom digestive tract surgical robot system according to the present invention; Figure 12This is a schematic diagram of the curved endoscope of a multi-degree-of-freedom gastrointestinal surgical robot system of the present invention. Figure 13 This is a schematic diagram of the snake-bone tractor theoretical model of a multi-degree-of-freedom gastrointestinal surgical robot system according to the present invention; Figure 14 This is a schematic diagram of a multi-degree-of-freedom gastrointestinal surgical robot system of the present invention, which uses a fiber optic grating to analyze the load perpendicular to the surface of the fixed clamping head by arranging a hypothetical force-sensitive elastomer clamping unit. Figure 15 This is a schematic diagram of the force-sensitive elastomer clamping unit of a multi-degree-of-freedom gastrointestinal surgical robot system of the present invention, which includes four hollow beams and four surface-metallized fiber optic gratings. Figure 16 This invention provides a multi-degree-of-freedom gastrointestinal surgical robot system. Fx Force diagram during action; Figure 17 This invention provides a multi-degree-of-freedom gastrointestinal surgical robot system. Fy Force diagram during action; Figure 18 This invention provides a multi-degree-of-freedom gastrointestinal surgical robot system. Fz A diagram showing the force distribution during the action. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, the present invention provides a multi-degree-of-freedom gastrointestinal surgical robot system, comprising: The platform has a pair of guide rails 4 on its end face; Main boom 3 is located on one side of the platform; The main boom drive device 1 is set on the platform, and its output end is connected to one end of the main boom 3 to provide power to the main boom 3. The main boom 3 is hollow inside. The deployment mechanism 6 is located at the other end of the main arm 3, away from the platform. The two sub-arms' main drive unit 2 is respectively set on the platform and slidably connected to the guide rail 4 in a one-to-one correspondence; the two sub-arms' main drive unit 2 moves linearly along the guide rail 4; the output end of the two sub-arms' main drive unit 2 passes through the main arm 3 and extends into the unfolding mechanism 6 to provide power to the unfolding mechanism 6. The unfolding mechanism 6 includes at least one snake-bone tube 6-1 and a force-sensitive elastomer clamping unit. The snake-bone tube 6-1 includes several sequentially arranged rotary joints, with adjacent rotary joints hinged together. The rotary joint at the first end communicates with a channel inside the main arm 3, and the rotary joint at the last end is connected to the force-sensitive elastomer clamping unit. Clamping force and three-dimensional force sensing are achieved through inverse kinematics calculations. The unfolding mechanism 6 also includes a curved endoscope 6-6 for providing a surgical field of view.

[0024] The main arm 3 and the deployment mechanism 6 are each driven by different guide wires.

[0025] In this embodiment, a passive section 5 is also included. The passive section 5 is disposed between the main drive device 2 for the two sub-arms and the main arm 3. The passive section 5 forms a receiving space for several sub-arm drive guidewires. The passive section 5 protects the guidewires and prevents them from being exposed.

[0026] like Figure 2As shown, the main boom drive device 1 is used to adjust the posture and extension of the main boom 3. Specifically, the main boom drive device 1 includes a first motor mounting base 1-1, several first motors 1-2, several first couplings 1-3, a motor support 1-4, a rear fixing plate 1-5, several support columns 1-6, several ball screws 1-8, a bearing seat 1-9, a front fixing plate 1-10, a nut extension piece 1-11, a main boom bracket 1-12, a light shaft 1-13, and a base 1-14; the base 1-14 is fixedly arranged relative to the platform; the first motor 1-2 mounting base 1-1, the rear fixing plate 1-5, and the front fixing plate 1-10 are parallel to each other and spaced apart, and the several support columns 1-6 pass through them sequentially. A first motor mounting base 1-1, a rear mounting plate 1-5, and a front mounting plate 1-10 are provided. One end of a support column 1-6 passes through the front mounting plate 1-10 and is fixedly connected to the main boom bracket 1-12. The interior of the main boom bracket 1-12 is connected to the interior of the main boom 3. The outlines of the first motor mounting base 1-1, the rear mounting plate 1-5, and the front mounting plate 1-10 are all circular, and their central axes are coaxial. Several support columns 1-6 are distributed at equal intervals around the central axis of the first motor mounting base 1-1. Several first motors 1-2 are provided on the end face of the first motor mounting base 1-1 away from the rear mounting plate 1-5. Several ball screws 1-8 are rotatably connected at both ends to the front fixed plate 1-10 and the rear fixed plate 1-5 via bearing seats 1-9, respectively. Nuts 1-7 are provided on the ball screws 1-8, forming a helical pair with the ball screws 1-8. Nut extension parts 1-11 are also fixedly provided on the nuts 1-7. A light shaft 1-13 is provided between the front fixed plate 1-10 and the rear fixed plate 1-5. One end of the nut extension part 1-11 extends towards the light shaft 1-13 and is slidably connected to the light shaft 1-13. Several first motors 1-2 are fixedly mounted on the first motor mounting base 1-1, and several... The output shaft of a motor 1-2 passes through a first motor mounting base 1-1 and is connected to several ball screws 1-8 via a first coupling 1-3. The first motor 1-2 outputs torque, which drives the nut to move linearly through the ball screws 1-8. The main arm 3 is also equipped with a main arm drive guide wire and a main arm push rod. The main arm drive guide wire and the main arm push rod are respectively fixedly connected to different nut extension parts 1-11. The main arm drive guide wire and the main arm push rod are also connected to the flexible section of the main arm. The main arm drive guide wire is used to adjust the bending of the flexible section of the main arm in a preset direction, and the main arm push rod is used to drive the extension and retraction of the flexible section of the main arm.

[0027] Specifically, such as Figure 3 As shown, the first motor mounting base 1-1 includes a mounting base 1-1-1, bolt holes 1-1-2 and a sleeve 1-1-3. The bolt holes 1-1-2 are used for fixing the first motor 1-2, the mounting base 1-1-1 is used to arrange the first motor 1-2, and the sleeve 1-1-3 is used to maintain the distance between the first motor mounting base 1-1 and the rear mounting plate 1-5.

[0028] When the first motor 1-2 drives several ball screws 1-8 to move linearly, the nut 1-7 is also constrained by the posture of the nut extension 1-11. The nut 1-7 further drives the main arm drive guide wire and the main arm push rod connected to it to move, thereby realizing the posture adjustment function of the main arm 3.

[0029] like Figure 4 and Figure 5 As shown, the two sub-arm drive units 2 each include a sub-arm drive unit 2-1, a quick-mount frame 2-2, a shaft fixing plate 2-3, a second motor 2-5, a motor fixing plate 2-6, a fixed housing 2-7, a driver assembly plate 2-8, a spring lever 2-9, a sub-arm motor fixing seat 2-10, and a shaft unit 2-11. The fixed housing is hollow inside and has an opening on one side. The motor fixing plate 2-6, the shaft fixing plate 2-3, and the sub-arm drive unit 2-1 are arranged sequentially at intervals along the normal direction of the opening of the fixed housing 2-7. The motor fixing plate 2-6 and the shaft unit 2-1 are... Fixed plates 2-3 are fixedly connected to fixed housing 2-7, and quick-mount bracket 2-2 is hinged to rotating shaft fixed plate 2-3; the second motor 2-5 is fixedly mounted on motor fixed plate 2-6, and the output shaft of the second motor 2-5 is connected to one end of the second coupling 2-4, the other end of the second coupling 2-4 passes through rotating shaft fixed plate 2-3 and is connected to rotating shaft unit 2-11, which is embedded in sub-arm drive unit 2-1; driver mounting plate 2-8 is fastened to rotating shaft fixed plate 2-3 and is used to install the second motor 2-5 driver; sub-arm drive... The moving unit 2-1 is provided with a protrusion, and the rotating shaft unit 2-11 is provided with a corresponding groove. The protrusion and the groove are matched one-to-one. One end of the spring lever 2-9 is connected to the sub-arm drive unit 2-1 through a pin to form a rotating pair. The other end of the spring lever 2-9 is provided with a hook-shaped structure, which is used to abut against the corresponding hook groove structure preset on the rotating shaft fixing plate 2-3, and to constrain the relative position of the sub-arm drive unit 2-1 and the rotating shaft fixing plate 2-3. The sub-arm motor fixing seat 2-10 and the motor fixing plate 2-6 are fastened together by bolts. The main arm 3 is also provided with several The main arm drives several guide wires, one end of which extends into the unfolding mechanism 6 and is fixedly connected to different positions of the unfolding mechanism 6. The other end of the guide wires is connected to the main arm drive unit 2-1, which is used to adjust the posture of the unfolding mechanism 6. The fixed housing 2-7 is also connected to the guide rail 4 to form a sliding pair. The fixed housing 2-7 is also connected to the push motor, which drives the fixed housing 2-7 to move linearly along the guide rail 4. The second motor 2-5 is used to wind or unwind several guide wires and adjust the posture of the unfolding mechanism 6.

[0030] The quick-assembly bracket 2-2 and the rotating shaft fixing plate 2-3 are connected by a pin, forming an openable structure. The quick-assembly bracket 2-2 can achieve an opening angle of approximately 180°, improving the assembly efficiency of the equipment. One end of the second coupling 2-4 is connected to the output shaft of the second motor 2-5, and the other end is connected to the rotating shaft unit 2-11, realizing the reliable transmission of power from the second motor to the sub-arm drive unit. The rotating shaft fixing plate 2-3 has an overall U-shaped cross-section structure. The rotating shaft fixing plate 2-3 is placed in the front half of the fixed housing 2-7, and is double-clamped and positioned axially and radially by the limiting bosses on the inner wall to prevent loosening. The driver assembly plate 2-8 is used to install the motor driver. It is placed in the rear half of the fixed housing 2-7 and is rigidly connected to the rotating shaft fixing plate 2-3 by multiple high-strength bolts, thus forming a stable "front and rear clamping" frame structure, effectively resisting vibration during operation. The motor mounting plate 2-6 is placed inside the fixed housing 2-7 to support and fix the second motor 2-5. The sub-arm motor mounting base 2-10 and the motor mounting plate 2-6 are fixedly connected by bolts to form a double-layer support structure, which effectively suppresses the jumping of the second motor during operation and improves the stability of system operation.

[0031] like Figure 6 As shown, the sub-arm drive unit 2-1 includes a reel cover 2-1-1, a reel base plate 2-1-2, a guide wheel 2-1-3, and a reel module 2-1-4. The reel cover 2-1-1 and the reel base plate 2-1-2 are directly opposite each other and fixedly installed, forming a gap between them. The guide wheel 2-1-3 is located within the gap area and is rotatably connected to the reel base plate 2-1-2. The reel module 2-1-4 is located between the reel cover 2-1-1 and the reel base plate 2-1-2. Corresponding through mounting holes are provided on the reel cover 2-1-1 and the reel base plate 2-1-2. The reel module 2-1-4 passes through the mounting holes and extends toward the rotating shaft fixing plate 2-3.

[0032] Among them, such as Figure 7As shown, the spool module 2-1-4 includes a shaft 2-1-4-6, two bearings 2-1-4-1, a spring 2-1-4-3, a winding wheel 2-1-4-4, and a stop block 2-1-4-5. The two bearings 2-1-4-1 are spaced apart along the axial extension direction of the shaft 2-1-4-6 and are correspondingly embedded in the mounting holes of the spool cover 2-1-1 and the spool base plate 2-1-2. The winding wheel 2-1-4-4 is fixedly mounted on the shaft. A spring 2-1-4-3 is fitted on the shaft 2-1-4-6 between the winding wheel 2-1-4-4 and the wheel cover 2-1-1. A stop block 2-1-4-5 is fitted on the shaft 2-1-4-6 between the winding wheel 2-1-4-4 and the wheel base plate 2-1-2. The spring 2-1-4-3 is used to absorb the instantaneous impact of the winding wheel 2-1-4-4 and maintain the stability of the two bearings 2-1-4-1. The winding wheel 2-1-4-4 rotates clockwise or counterclockwise under the drive of the second motor to realize the winding and unwinding action of the guide wire driven by the sub-arm, thereby adjusting the posture of the unfolding mechanism 6.

[0033] See appendix Figure 8 , Figure 9 and Figure 10The deployment mechanism 6 also includes a deployment push rod 6-2, two deployment connecting rods 6-3, a hollow end cap 6-4, a deployment channel 6-5, a curved endoscope 6-6, and a force sensing unit 6-8. The end cap 6-4 is hollow inside and is used to connect to the end of the main arm 3 away from the main arm drive device 1. The end cap 6-4 has an endoscope hole. The deployment push rod 6-2 includes a connector 6-2-1 and a rod body 6-2-2. The rod body 6-2-2 is inserted into the end cap 6-4 and fixedly connected to the end cap 6-4. The connector 6-2-1 is fixedly connected to one end of each of the two deployment connecting rods 6-3. The other ends of the two unfolding connecting rods 6-3 are connected to the unfolding channel 6-5; the unfolding channel 6-5 has a channel body, and the snake bone tube 6-1 is connected to the channel body by metal glue, thereby making the integrated channel and the channel body interconnected; the curved endoscope 6-6 is fixed in the endoscope hole of the end 6-4 by metal glue; the force-sensitive elastomer clamping unit 6-7 is connected to the end of the snake bone tube 6-1 away from the end 6-4 by metal glue, and the force-sensitive elastomer clamping unit 6-7 includes a fixed clamp head, a movable clamp head, a rotating pin, and a clamp support, with an outwardly extending fixed clamp head at one end of the clamp support. The clamp head has a rotating pin mounted on and rotatably connected to the fixed clamp head. The movable clamp head is fixedly mounted on the rotating pin. A force sensing unit 6-8 is located at the other end of the clamp support. The force sensing unit 6-8 includes four hollow beams and six surface-metallized fiber Bragg gratings. The four hollow beams are inclined relative to the central axis of the clamp linkage. The four surface-metallized fiber Bragg gratings are correspondingly arranged inside the hollow beams and are in a fixed tensioned state at both ends, forming a fiber Bragg grating array. When the force-sensitive elastic body clamping unit is subjected to an external three-dimensional force, the force-sensitive... The elastomer clamping unit amplifies the strain corresponding to the three-dimensional force and transmits it to the fiber Bragg grating array. It obtains the wavelength change of the fiber Bragg grating array and decouples it to achieve real-time detection and analysis of the three-dimensional force. The other two surface-metallized fiber Bragg gratings are used to measure the clamping force of the force-sensitive elastomer clamping unit and achieve temperature compensation decoupling. One sub-arm drive guidewire also passes through the snake bone tube and is fixedly connected to the rotating pin. It is used to drive the rotating pin to rotate or reset, thereby opening or resetting the moving clamp head. The snake bone tube 6-1 is connected to the four sub-arm drive guidewires to achieve rotation in two directions.

[0034] The unfolding channel 6-5 includes a channel body 6-5-2 and a connecting ear plate 6-5-1. The channel body 6-5-2 and the unfolding connecting rod 6-3 are fixed by bolts, and the connecting ear plate 6-5-1 is threadedly connected to the end 6-4 by bolts.

[0035] like Figure 11As shown, the snake-bone tube 6-1 includes a hollow, adjacently arranged head rotation joint 6-1-4, several intermediate rotation joints 6-1-2, and a tail rotation joint 6-1-1. The head rotation joint 6-1-4 has symmetrically arranged slots extending away from the tail end 6-4. Each intermediate rotation joint 6-1-2 has a symmetrically arranged arc-shaped protrusion at one end, extending towards the tail end 6-4. The other end of each intermediate rotation joint 6-1-2 also has symmetrically arranged outwardly extending slots, which are fitted with the arc-shaped protrusions with a clearance. The slots or arc-shaped protrusions of adjacent rotation joints... The shaped protrusions are positioned opposite each other, and the slots at both ends of the same rotary joint are spaced 90° apart from the shaped protrusions. Each rotary joint is equipped with a wiring ring, which has four through-holes for the sub-arm drive wires and two fiber optic holes. The four sub-arm drive wire holes are evenly distributed relative to the central axis of the wiring ring and are fixedly connected to the end rotary joint 6-1-1. The two fiber optic holes are used to form channels for two surface-metallized fiber optic gratings for measuring the clamping force of the force-sensitive elastomer clamping unit. In the snake tube, any two non-adjacent sub-arm drive wires serve as pitch adjustment wires and offset adjustment wires, respectively. Figure 11 The image also shows the connection configuration of the two intermediate rotary joints 6-1-2 and 6-1-3.

[0036] like Figure 12 As shown, the curved endoscope 6-6 includes a camera 6-6-1 and an arc-shaped connecting part 6-6-2. The camera 6-6-1 is embedded at one end of the arc-shaped connecting part 6-6-2, and the other end of the arc-shaped connecting part 6-6-2 is embedded in the endoscope aperture of the end cap 6-4. The curved endoscope 6-6 can acquire real-time images of the surgical site and output them for display, which is beneficial for visualizing the surgical procedure.

[0037] The inverse kinematics calculations mentioned above include the following: establishing a geometric and kinematic model; simplifying the deployment mechanism using a piecewise constant curvature model; assuming that each rotary joint of the deployment mechanism maintains constant curvature during motion; establishing a coordinate system at each rotary joint of the snake-like tube; and establishing a base coordinate system at the curved endoscope. The transformation matrix is ​​derived based on geometric relationships. i The coordinate system of the rotational joint is to i +1 homogeneous transformation matrix of the coordinate system of the rotation joints i ∈ N , NGiven the total number of rotary joints, the global transformation matrix from the base coordinate system to the force-sensitive elastic body clamping unit is further obtained. A kinematic model is established using the global exponential product method based on spinor theory, representing the motion of each rotary joint as an exponential transformation along a helical axis. The pose of the end rotary joint of the snake tube is obtained by multiplying the transformations of all rotary joints. Inverse kinematics is solved, and based on the constant curvature assumption and geometric relationships, the bending motion of the snake tube is decomposed into the superposition of pitch and yaw rotary joints. The required rotation angle of each pitch and yaw rotary joint is calculated, and a mathematical relationship is established between the rotation angle and the length change of the four sub-arm drive guidewires of the snake tube, realizing the correlation between the operation command and the actual action of the deployment mechanism.

[0038] The deployment mechanism proposed in this invention uses a mechanical structure for meshing connection, with guide wires welded only at the distal end. A kinematic model of the deployment mechanism is established using the segmented constant curvature method, and a Cartesian coordinate system is established. x , y , z Let represent the coordinates of snake bone tube 6-1 in the Cartesian coordinate system, and let . α and θ The corners and bends of the snake bone tube 6-1 are respectively established as follows: Figure 13 The geometric theoretical model shown establishes a coordinate system at the bottom of the front end rotary joint. Establish a coordinate system at the top of the head joint. Each coordinate system x The axis points to one of the guide wires. z The shaft is along the axial direction. y The axes are determined by the right-hand rule, from the coordinate system arrive The homogeneous transformation matrix is Formula 1, where R i Where is the bending radius, α i Yaw angle θ i For the bending angle, z express z axis, rot Indicates rotation transformation, trans This indicates a translation transformation.

[0039] Establish a base coordinate system at the endoscope tip Establish a coordinate system at the starting end of snake bone tube 6-1. Establish a coordinate system at the end of the snake bone tube 6-1. A coordinate system is established at the end of the end effector, i.e., the force-sensitive elastomer clamping unit. In the base coordinate system z The axis coincides with the central axis. xThe axis points to the left side of the snake bone tube 6-1 and is perpendicular to it. z axis, y The axis is determined according to the right-hand rule. The position of the end effector can be obtained from the pose space by transforming it using homogeneous transformation matrices of the global and local coordinate systems. First, the first translation segment is moved along... z Axial movement distance d 1. Obtain from the base coordinate system To coordinate system homogeneous transformation matrix , , Formula 2.

[0040] A kinematic model of the robot was established based on the global exponential product method, simplifying the modeling process. Only a base coordinate system {B} and an end coordinate system {T} were established, and the rotational joints of the snake tube 6-1 were described in these two coordinate systems. In contrast to the traditional Denavit-Hartenberg modeling method, the kinematic transformation matrix of the end coordinate system {T} relative to the base coordinate system {B} was given as... Formula 3, where Π represents a series of multiplication operations. , formula 4, θ i For the bending angle, It is the first i The antisymmetric matrix of the helical axial quantities of the nth revolute joint in the base coordinate system {B}, where the nth i The torsion vectors of the rotational joints relative to the base coordinate system {B} are: , It is the helical axis vector of the cylinder block transformation. It is the Lie algebra vector corresponding to the initial installation error. ω i and v i These are the rotational and translational components of the i-th rotational joint, respectively. Differentiating both sides of Equation 3 yields the pose error model for the continuous bending segment: , Formula 5, The pose matrix of the end effector. The pose matrix of the end effector The inverse matrix, This represents the deviation between the actual pose and the nominal pose. As shown in Formula 5, the error of the end effector is determined by the screw force. The bending angle of the snake bone tube θ Lie algebra vector corresponding to initial installation error Caused, respectively represented as That is, screw error, joint error, and initial installation error, let's assume... The actual end effector pose obtained from measurement data, The nominal end effector pose, Represented as and The deviation.

[0041] By aligning the axis of the rotary joint with the link coordinate system Z The axis coincides, and a point on the axis coincides with the origin of the link coordinate system, thus standardizing the nominal torsion vector parameter and protecting only the axis. z The definition of axis direction and origin position allows the error of the actual torsion vector to be decomposed into only the rotation direction vector. of x / y Components and coordinate deviation of x / y The component consists of four independent parameters.

[0042] No. i The torsion vectors of the rotational joints relative to the base coordinate system {B} are: , No. i A rotary joint in its associated link coordinate system { I The twist vector under} is , Let be the rotation direction vector. For linear velocity components, Represents the link coordinate system { I The homogeneous transformation matrix relative to the base coordinate system satisfies , Formula 6, , Formula 7, This indicates an accompanying element.

[0043] When the torsion vector When the coordinate system of the link changes, { I} Synchronous changes, according to the coordinate system establishment rules mentioned above, the link coordinate system { I Torsion vector under} It remains constant throughout the analysis of the twist vector. When there is a small deviation, temporarily fix the link coordinate system { I}, the actual twist vector With nominal twist vector The deviation is equivalent to In a fixed coordinate system { I Deviation under} , formula 8, , Formula 9, For the rotation direction vector in x , y and z Components of the axis, This represents the axial component of the coordinate deviation. Since the rotation direction vector of the rotary joint needs to satisfy the unit vector constraint... Therefore, in the small deviations near the nominal value Only two parameters need to be considered. And when the second-order small error is ignored, the coordinate deviation... of z Axial component with respect to joint torsional vector No impact, therefore can be fixed. Only two independent parameters are required. Describing coordinate deviation Therefore, the independent vector parameters of the rotary joint are defined as follows: .

[0044] The forward kinematic model can be represented as , formula 10, Formula 11, the error model can be expressed as: Formula 12 shows that the error of the end effector is determined by the independent vector parameters of the joint. η Joint angles q Lie algebra vector corresponding to initial installation error Caused, respectively represented as , , Formula 13, I Let be the identity matrix, with the superscript -1 indicating the inverse of the matrix. It is converted to the linear twisted vector error in the Lie algebra of se(3) by a logarithmic mapping: , Formula 14, Formula 15, where the superscript V indicates vectorization operation.

[0045] Consider a serpentine tube with N rotational elements, including N / 2 pitch elements and N / 2 yaw elements, moving in the pitch plane (YOZ) and yaw plane (XOZ), respectively. The overall bending angle of the serpentine tube is Θ, and the angle between the bending plane and the y-axis is Φ, as shown below. Figure 13 As shown, given the coordinates (xp, yp, zp) of the terminal point P, the values ​​of Θ and Φ can be obtained based on the assumption of constant curvature. , Formula 16, Formula 17, based on the constant curvature assumption and the vector composition principle, the bending motion of the manipulator can be considered as N / 2 pitch joints rotating around... x The shaft and N / 2 yaw joints around y The vector superposition of the axis rotations yields: , Formula 18.

[0046] Since the motion trajectory of the snake-bone tube end is a continuous curved surface, a one-to-one correspondence with the master arm coordinates cannot be achieved. Therefore, a master-slave control based on proportional control is adopted. The motion space of the master arm with respect to horizontal and vertical displacements is mapped to the pitch and yaw plane bending motions of the manipulator by setting proportional coefficients. This master-slave mapping relationship is shown below: , Formula 19, Formula 20, where x , y These represent the displacements of the main hand in two directions. and They are respectively y direction and x Directional bending angle, k 1 and k 2 represents the corresponding mapping ratio coefficients. , Formula 21.

[0047] The known pitch angle can be obtained from the above formula. θ 1 and yaw angle θ 2. The bending pattern of the orthogonal serpentine hinge is similar in both the pitch and bending planes, and can be derived in the same way. The following example focuses on the pitch plane. In the YOZ pitch plane, the guidewire undergoes both active and passive bending deformations. Active bending refers to the deformation of the pitch guidewire between pitch units, while passive bending refers to the bending of the pitch guidewire between yaw units due to their deformation. By superimposing the active and passive bending based on geometric relationships, the elongation and contraction of a pair of guidewires in this YOZ pitch plane can be calculated as follows: , Formula 22, h The axial length of the rotary joint; subscript l and subscript r Represents a pair of guidewires that drive the rotation of the serpentine tube; △ l This represents the elongation and contraction of the guidewire. Similarly, the elongation and contraction of a pair of guidewires within the yaw plane XOZ are as follows: Formula 23. Therefore, to reach the target point P(x,y,z), the changes in the four guidewires are: Formula 24 shows that the rope lengths of the four guide wires can be calculated using the following formula: , Formula 25, L It is the initial length of the guidewire.

[0048] This embodiment, to achieve clamping force and three-dimensional force sensing, specifically includes the following: Based on the structure of the force-sensitive elastomer clamping unit, a four-channel fiber optic force sensor is constructed by four hollow beams and four corresponding surface-metallized fiber optic gratings inside; a mathematical relationship is established between the external force and the microscopic deformation of the hollow beam containing each fiber optic grating; based on the principle of fiber optic gratings, a relationship between wavelength drift and fiber optic grating strain is established, and the real-time wavelength drift is obtained; a mapping relationship between wavelength drift and three-dimensional force is established, and finally, the calculated three-dimensional force and clamping force are output. The theoretical model of the fiber optic clamping-three-dimensional force sensing clamp is then derived.

[0049] See Figure 14 When a surface-metallized fiber grating is arranged inside the force-sensitive elastomer clamping unit, the load perpendicular to the clamping surface is analyzed. F The strain generated by the force-sensitive elastic clamping unit during operation. The actual load on the four hollow beams, i.e., the rods. F p and bending moment M for: Formula 26 states that when a unit force is applied vertically to the rod, under a unit load, the virtual internal force and virtual bending moment of the rod under the unit load are: Formula 27, the displacement of the rod in the vertical direction is , Formula 28, l Let be the length of the rod; when a unit couple is applied, the angle of rotation of the rod along the vertical direction is . , Formula 29, EI To determine the bending stiffness, the strain of the fiber grating can be calculated based on geometric relationships. , Formula 30.

[0050] So in F N The wavelength shift of the fiber grating under the action of the action is , Formula 31, λ 0 represents the initial center wavelength of the fiber grating. ρ e For the effective elastic coefficient, ε F This represents the axial strain at the location of the fiber grating.

[0051] See Figure 15 The sensing structure of the force-sensitive elastomer clamping unit includes four hollow beams, each containing a surface-metallized fiber Bragg grating. The strain generated by the force-sensitive elastomer clamping unit under forces applied in different directions is analyzed.

[0052] See Figure 16 In (a), when force F x When in operation, the upper cover of the sensing structure is analyzed. From the equilibrium condition, it can be seen that: , Formula 32, F x1 , F x2 , F x3 , F x4 The horizontal component of the force exerted by the four hollow beams on the upper end cap. F x This is the external load acting on the upper surface of the sensor. F z1 ,F z2 , F z3 , F z4 The vertical component of the force exerted by the four hollow beams on the upper end cap. R The radius of the sensor's upper cover. The angle between the hollow beam and the vertical plane. θ It is the angle between the projection of the hollow beam onto the XOY plane and the X-axis. h The distance from the point of application of the load to the upper cover. M y1 , M y2 , M y3 , M y4 These are the bending moments of the four hollow beams about the upper end cap about the Y-axis; when F x When in operation, the actual load and actual bending moment on hollow beam 1, i.e., rod 1, are as follows: Formula 33, where F N , M Let X be the axial force on hollow beam 1 and the bending moment perpendicular to the XOY plane along hollow beam 1, respectively. A unit force in the X direction is applied at the contact point between rod 1 and the upper end cap. Under a unit load, the equations for the axial force and bending moment of hollow beam 1 are: Formula 34, see Figure 16 In (b), the magnitude of the transverse displacement of hollow beam 1 is Formula 35, here l Let be the length of the hollow beam 1. A unit moment perpendicular to the XOY plane is applied along the hollow beam 1 at the contact point between the hollow beam 1 and the upper end cap. Under the action of the unit moment, the equations for the axial force and bending moment of the hollow beam 1 are: Formula 36, ​​the lateral rotation angle of hollow beam 1 is... Formula 37: When a unit force is applied along the rod direction at the contact point between the hollow beam 1 and the upper end cap, the equations for the axial force and bending moment of the hollow beam 1 under a unit load are as follows: Formula 38, the magnitude of the displacement of hollow beam 1 along its length is , Formula 39, A Let be the cross-sectional area of ​​rod 1.

[0053] when F x When in operation, the actual load and actual bending moment on hollow beam 2, i.e., rod 2, are respectively Formula 40, here F N and MLet X be the axial force on hollow beam 2 and Y be the bending moment along hollow beam 2 perpendicular to its projection plane, respectively. A unit force in the X direction is applied at the contact point between hollow beam 2 and the upper end cap. Under this unit load, the equations for the axial force and bending moment of hollow beam 2 are: Formula 41, the magnitude of the transverse displacement of hollow beam 2 is Formula 42: A unit moment perpendicular to the XOY plane is applied along the rod at the contact point between the hollow beam 2 and the upper end cap. Under the action of the unit moment, the equations for the axial force and bending moment of the hollow beam 2 are as follows: Formula 43, the lateral rotation angle of hollow beam 2 is... Formula 44, here l Let be the length of hollow beam 2. A unit force in the rod direction is applied at the contact point between hollow beam 2 and the upper end cap. Under this unit load, the equations for the axial force and bending moment of hollow beam 2 are: Formula 45, the magnitude of the displacement of the hollow beam 2 along its length is , Formula 46.

[0054] when F x When in operation, the actual load and actual bending moment on the hollow beam 3, i.e., rod 3, are respectively Formula 47, here F N and M Let X be the axial force on rod 3 and the bending moment perpendicular to the XOY plane along rod 3, respectively. A unit force in the X direction is applied at the contact point between rod 3 and the upper end cap. Under a unit load, the equations for the axial force and bending moment of rod 3 are: Formula 48, the magnitude of the lateral displacement of rod 3 is Formula 49: A unit moment perpendicular to the XOY plane is applied along the rod at the contact point between rod 3 and the upper end cap. Under the action of the unit moment, the equations for the axial force and bending moment of rod 3 are as follows: Formula 50, the angle of rotation of rod 3 along the lateral direction is... Formula 51: When a unit force is applied along the rod direction at the contact point between rod 3 and the upper end cap, the equations for the axial force and bending moment of rod 3 under a unit load are as follows: Formula 52, the magnitude of the displacement of rod 3 along the rod direction is , Formula 53.

[0055] when F x When in operation, the actual load and actual bending moment on the hollow beam 4, i.e., rod 4, are respectively Formula 54, here F N and MLet X be the axial force on rod 4 and the bending moment along rod 4 perpendicular to the XOY plane, respectively. A unit force in the X direction is applied at the contact point between rod 4 and the upper end cap. Under a unit load, the equations for the axial force and bending moment of rod 4 are: Formula 55, the magnitude of the lateral displacement of rod 4 is Formula 56: A unit moment perpendicular to the XOY plane is applied along the rod at the contact point between rod 4 and the upper end cap. Under the action of this unit moment, the equations for the axial force and bending moment of rod 4 are as follows: Formula 57, the lateral rotation angle of rod 4 is... Formula 58 states that at the contact point between rod 4 and the upper end cap, a unit force is applied along the rod direction. Under a unit load, the equations for the axial force and bending moment of rod 4 are obtained as follows: Formula 59, the magnitude of the displacement of rod 4 along the rod direction is , Formula 60.

[0056] Based on this, by solving the equilibrium equations, we can obtain... F x1 , F x2 , F x3 , F x4 , M y1 , M y2 , M y3 , M y4 Eight unknowns are used to calculate all deformation parameters. Formula 61 analyzes the strain on the optical fiber. For rod 1, based on geometric relationships, the strain of the fiber grating at rod 1 can be obtained. Formula 62, strain of the fiber grating at rod 2 Formula 63, strain of the fiber grating at rod 3 Formula 64, strain of the fiber grating at rod 4 Formula 65 yields the force. F x Fiber Bragg grating wavelength drift matrix during operation , Formula 66, F x Fiber optic sensitivity during operation , i =1,2,3,4, formula 67, This is the stiffness matrix, used to describe the conversion relationship between load and wavelength drift.

[0057] when F y When in action, the force conditions of rods 1 and 3 are the same as those of rods 3 and 4. Fx When the action is performed, the force conditions of rods 2 and 4 are the same, and the force conditions of rods 2 and 4 are similar to those of rods 4 and 5. F x When in action, the force conditions of rods 3 and 1 are the same (see below). Figure 17 Therefore, the strain of the fiber grating at rod 1 can be obtained. Formula 68, strain of the fiber grating at rod 2 Formula 69, strain of the fiber grating at rod 3 Formula 70, strain of the fiber grating at rod 4 Formula 71 yields the force. F y Fiber Bragg grating wavelength drift matrix during operation , Formula 72, F y Fiber optic sensitivity during operation , Formula 73.

[0058] when F z When in operation, all four rods experience identical forces; therefore, only rod 1 needs to undergo a force analysis. (See [reference]). Figure 18 Analyzing the upper cover of the sensor, it can be seen from the equilibrium condition that... , Formula 74; when F z When in action, the actual load and actual bending moment on rod 1 are respectively Formula 75; When a transverse unit force is applied at the contact point between rod 1 and the upper end cap, the equations for the axial force and bending moment of rod 1 under a unit load are as follows: Formula 76, the magnitude of the displacement of rod 1 along the X direction is A unit moment perpendicular to the projection plane is applied along the rod at the contact point between rod 1 and the upper end cap. Under the action of the unit moment, the equations for the axial force and bending moment of rod 1 are as follows: Formula 77, the angle of rotation of rod 1 along the X direction is: Formula 78: When a unit force in the rod direction is applied at the contact point between rod 1 and the upper end cap, the equations for the axial force and bending moment of rod 1 under a unit load are as follows: Formula 79, the magnitude of the displacement of rod 1 along the rod direction is Formula 80 analyzes the strain on the optical fiber. For rod 1, based on geometric relationships, the strain of the fiber grating at rod 1 can be obtained. Formula 81 yields the following result: F z Fiber Bragg grating wavelength drift matrix during operation , Formula 82, F z Fiber optic sensitivity during operation , Formula 83.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-degree-of-freedom gastrointestinal surgical robot system, characterized in that, include: The platform has a pair of guide rails (4) on its end face. The main boom (3) is located on one side of the platform; The main boom drive device (1) is set on the platform, and its output end is connected to one end of the main boom (3) to provide power to the main boom (3). The main boom (3) is hollow inside. The unfolding mechanism (6) is located at the other end of the main arm (3) away from the platform. The two sub-arm drive units (2) are respectively set on the platform and slidably connected to the guide rails (4) one by one; the two sub-arm drive units (2) move linearly along the guide rails (4); the output end of the two sub-arm drive units (2) passes through the main arm (3) and extends into the unfolding mechanism (6) to provide power to the unfolding mechanism (6); The unfolding mechanism (6) includes at least one snake bone tube (6-1) and a force-sensitive elastomer clamping unit. At least one snake bone tube (6-1) includes several sequentially arranged rotary joints. Adjacent rotary joints are hinged together. The interior of the rotary joint at the head end is connected to the channel inside the main arm (3). The rotary joint at the end end is connected to the force-sensitive elastomer clamping unit. Through inverse kinematics calculation, clamping force and three-dimensional force perception are realized. The main boom drive device (1) includes a first motor mounting base (1-1), several first motors (1-2), several first couplings (1-3), a motor support (1-4), a rear mounting plate (1-5), several support columns (1-6), several ball screws (1-8), a bearing seat (1-9), a front mounting plate (1-10), a nut extension (1-11), a main boom bracket (1-12), a light shaft (1-13), and a base (1-14); the base (1-14) is fixedly set relative to the platform; the first motor mounting base (1-1), the rear mounting plate (1-2), the first motor (1-2), the first coupling (1-3), the first motor support (1-4), the first motor (1-5), the first motor (1-6), the first coupling (1-7), the first motor (1-8), the first motor (1-9), the first motor (1-10), the first motor (1-11), the first motor (1-2), the first coupling (1-3), the first motor (1-4), the first motor (1-5), the first motor (1-6), the first motor (1-7), the first motor (1-8), the first motor (1-9), the first motor (1-10), the first motor (1-11), the first motor (1-2), the first motor ...12), the first motor (1-13), the first motor (1-14), the first motor (1-15), the first motor (1-16), the first motor (1-17), the first motor (1-18), the first motor (1-19), the first motor (1-10), the first motor ( -5) and the front fixing plate (1-10) are parallel to each other and spaced apart. Several support columns (1-6) are arranged to pass through the first motor fixing seat (1-1), the rear fixing plate (1-5) and the front fixing plate (1-10) in sequence. One end of the support column (1-6) also passes through the front fixing plate (1-10) and is fixedly connected to the main boom bracket (1-12). The inside of the main boom bracket (1-12) is connected to the inside of the main boom (3). The outlines of the first motor fixing seat (1-1), the rear fixing plate (1-5) and the front fixing plate (1-10) are all circular, and the central axis is coaxial. Several support columns (1-5) are arranged to pass through the first motor fixing seat (1-1), the rear fixing plate (1-5) and the front fixing plate (1-10) in sequence. The columns (1-6) are evenly spaced circumferentially relative to the central axis of the first motor mounting base (1-1); several first motors (1-2) are located on the end face of the first motor mounting base (1-1) away from the rear mounting plate (1-5); the two ends of several ball screws (1-8) are rotatably connected to the front mounting plate (1-10) and the rear mounting plate (1-5) respectively through bearing seats (1-9), and nuts are provided on the ball screws (1-8). The nuts and ball screws (1-8) form a helical pair, and nut extension parts (1-11) are also fixedly provided on the nuts. The front mounting plate (1-10) A light shaft (1-13) is provided between the nut extension (1-11) and the rear fixed plate (1-5). One end of the nut extension (1-11) extends toward the light shaft (1-13) and is slidably connected to the light shaft (1-13). Several first motors (1-2) are fixedly mounted on the first motor mounting base (1-1), and the output shafts of the several first motors (1-2) pass through the first motor mounting base (1-1) and are connected to several ball screws (1-8) through the first coupling (1-3). The first motors (1-2) output torque, which drives the nut to move linearly through the ball screws (1-8). The main arm (3) is also equipped with a main arm drive guide wire and a main arm push rod. The main arm drive guide wire and the main arm push rod are respectively fixedly connected to different nut extension parts (1-11). The main arm drive guide wire and the main arm push rod are also connected to the flexible section of the main arm. The main arm drive guide wire is used to adjust the flexible section of the main arm to bend in a preset direction. The main arm push rod is used to drive the flexible section of the main arm to extend and retract. It also includes a passive section (5), which is located between the two sub-arm main drive device (2) and the main arm (3). The passive section (5) forms a space for accommodating several sub-arm drive guide wires.

2. The multi-degree-of-freedom gastrointestinal surgical robot system according to claim 1, characterized in that, The two sub-arm drive units (2) each include a sub-arm drive unit (2-1), a quick-mount frame (2-2), a rotating shaft fixing plate (2-3), a second motor (2-5), a motor fixing plate (2-6), a fixed housing (2-7), a driver assembly plate (2-8), a spring lever (2-9), a sub-arm motor fixing seat (2-10), and a rotating shaft unit (2-11). The fixed housing is hollow inside and has an opening on one side. The motor fixing plate (2-6), the rotating shaft fixing plate (2-3), and the sub-arm drive unit (2-1) are arranged sequentially at intervals along the normal direction of the opening of the fixed housing (2-7). 6) Both the shaft fixing plate (2-3) and the rotating shaft fixing plate (2-7) are fixedly connected to the fixed housing (2-7), and the quick-mount bracket (2-2) is hinged to the rotating shaft fixing plate (2-3); the second motor (2-5) is fixedly mounted on the motor fixing plate (2-6), and the output shaft of the second motor (2-5) is connected to one end of the second coupling (2-4). The other end of the second coupling (2-4) passes through the rotating shaft fixing plate (2-3) and is connected to the rotating shaft unit (2-11). The rotating shaft unit (2-11) is embedded in the sub-arm drive unit (2-1); the driver assembly plate (2-8) is fastened to the rotating shaft fixing plate (2-3) and is used to install the second motor (2-7). -5) Driver; The sub-arm drive unit (2-1) is provided with a protrusion, and the rotating shaft unit (2-11) is provided with a corresponding groove, with the protrusion and the groove corresponding to each other; One end of the spring lever (2-9) is connected to the sub-arm drive unit (2-1) through a pin to realize a rotating pair connection, and the other end of the spring lever (2-9) is provided with a hook-shaped structure, which is used to resist the corresponding hook groove structure preset on the rotating shaft fixing plate (2-3) to constrain the relative position of the sub-arm drive unit (2-1) and the rotating shaft fixing plate (2-3); The sub-arm motor fixing seat (2-10) and the motor fixing plate (2-6) are fastened together by bolts; The main arm (3) inside Several sub-arm drive guide wires are also provided. One end of each sub-arm drive guide wire extends into the unfolding mechanism (6) and is fixedly connected to different positions of the unfolding mechanism. The other end of each sub-arm drive guide wire is connected to the sub-arm drive unit (2-1). The sub-arm drive unit (2-1) is used to adjust the posture of the unfolding mechanism (6). The fixed shell (2-7) is also connected to the guide rail (4) to form a sliding pair. The fixed shell (2-7) is also connected to the push motor. The push motor drives the fixed shell (2-7) to move linearly along the guide rail (4). The second motor (2-5) is used to wind or unwind the sub-arm drive guide wires and adjust the posture of the unfolding mechanism (6).

3. The multi-degree-of-freedom gastrointestinal surgical robot system according to claim 2, characterized in that, The sub-arm drive unit (2-1) includes a reel cover (2-1-1), a reel base plate (2-1-2), a guide wheel (2-1-3), and a reel module (2-1-4). The reel cover (2-1-1) and the reel base plate (2-1-2) are directly opposite each other and fixedly installed, forming a gap between them. The guide wheel (2-1-3) is located within the gap area and is rotatably connected to the reel base plate (2-1-2). The reel module (2-1-4) is located between the reel cover (2-1-1) and the reel base plate (2-1-2). Corresponding through mounting holes are provided on the reel cover (2-1-1) and the reel base plate (2-1-2). The reel module (2-1-4) passes through the mounting holes and extends toward the rotating shaft fixing plate (2-3). The spool module (2-1-4) includes a shaft (2-1-4-6), two bearings (2-1-4-1), a spring (2-1-4-3), a winding wheel (2-1-4-4), and a stop (2-1-4-5). The two bearings (2-1-4-1) are spaced apart along the axial extension direction of the shaft (2-1-4-6) and are correspondingly embedded in the mounting holes of the spool cover (2-1-1) and the spool base plate (2-1-2). The winding wheel (2-1-4-4) is fixedly mounted on the shaft (2-1-4-6). On 2-1-4-6), a spring (2-1-4-3) is fitted on the shaft (2-1-4-6) between the winding wheel (2-1-4-4) and the wheel cover (2-1-1). A stop block (2-1-4-5) is fitted on the shaft (2-1-4-6) between the winding wheel (2-1-4-4) and the wheel base plate (2-1-2). The spring (2-1-4-3) is used to absorb the instantaneous impact of the winding wheel (2-1-4-4) and maintain the stability of the two bearings (2-1-4-1).

4. The multi-degree-of-freedom gastrointestinal surgical robot system according to claim 2, characterized in that, The unfolding mechanism (6) further includes an unfolding push rod (6-2), two unfolding connecting rods (6-3), a hollow end (6-4), an unfolding channel (6-5), a curved endoscope (6-6), and a force sensing unit (6-8); the end (6-4) is hollow inside and is used to connect to the end of the main arm (3) away from the main arm drive device (1), and the end (6-4) has an endoscope hole; the unfolding push rod (6-2) includes a connector (6-2-1) and a rod body (6-2-2), the rod body (6-2-2) is inserted into the end (6-4) and fixedly connected to the end (6-4), the connector... (6-2-1) is fixedly connected to one end of each of the two unfolding connecting rods (6-3), and the other end of each of the two unfolding connecting rods (6-3) is connected to the unfolding channel (6-5); the unfolding channel (6-5) has a channel body, and the snake bone tube (6-1) is connected to the channel body by metal glue, thereby enabling the integrated channel and the channel body to communicate with each other; the curved endoscope (6-6) is fixed in the endoscope hole of the end (6-4) with metal glue; the force-sensitive elastomer clamping unit is connected to the end of the snake bone tube (6-1) away from the end (6-4) by metal glue, and the force-sensitive elastomer clamping unit includes a fixed clamp head, a movable clamp head, and a rotating clamp head. The clamping unit comprises a pin and a clamping bracket. One end of the clamping bracket has an outwardly extending fixed clamping head. A rotating pin is mounted on the fixed clamping head and rotatably connected to it. A movable clamping head is fixedly mounted on the rotating pin. The other end of the clamping bracket has a force sensing unit (6-8). The force sensing unit (6-8) includes four hollow beams and six surface-metallized fiber gratings. The four hollow beams are inclined relative to the central axis of the clamping linkage. The four surface-metallized fiber gratings are correspondingly arranged inside the hollow beams and are in a fixed tensioned state at both ends, forming a fiber grating array. When the force-sensitive elastic body clamping unit is subjected to... When an external three-dimensional force is applied, the force-sensitive elastomer clamping unit amplifies the strain corresponding to the three-dimensional force and transmits it to the fiber grating array. It obtains the wavelength change of the fiber grating array and decouples it to realize the real-time detection and analysis of the three-dimensional force. The other two surface-metallized fiber gratings are used to measure the clamping force of the force-sensitive elastomer clamping unit and realize temperature compensation decoupling. One sub-arm drive guidewire also passes through the snake bone tube and is fixedly connected to the rotating pin to drive the rotating pin to rotate or reset, thereby opening or resetting the moving clamp head. The snake bone tube (6-1) is connected to the four sub-arm drive guidewires to realize rotation in two directions.

5. The multi-degree-of-freedom gastrointestinal surgical robot system according to claim 4, characterized in that, The snake-bone tube (6-1) includes a hollow, adjacently arranged head rotation joint (6-1-4), several intermediate rotation joints (6-1-2), and a tail rotation joint (6-1-1). The head rotation joint (6-1-4) has symmetrically arranged slots extending away from the tail end (6-4). Each intermediate rotation joint (6-1-2) has symmetrically arranged arc-shaped protrusions at one end, extending towards the tail end (6-4). The other end of each intermediate rotation joint (6-1-2) also has symmetrically arranged outwardly extending slots. The slots or arc-shaped protrusions of the adjacent rotary joints are aligned, with the slots and arc-shaped protrusions at both ends of the same rotary joint spaced 90° apart. Each rotary joint is provided with a wiring ring, which has four through-holes for the sub-arm drive wire guides and two fiber optic holes. The four sub-arm drive wire guide holes are evenly distributed relative to the central axis of the wiring ring and are fixedly connected to the end rotary joint (6-1-1). The two fiber optic holes are used to form channels for the two surface-metallized fiber optic gratings for measuring the clamping force of the force-sensitive elastomer clamping unit. In the snake tube, any two non-adjacent sub-arm drive guidewires serve as pitch adjustment guidewires and offset adjustment guidewires, respectively.

6. The multi-degree-of-freedom gastrointestinal surgical robot system according to claim 4, characterized in that, The curved endoscope (6-6) includes a camera (6-6-1) and an arc-shaped connecting part (6-6-2). The camera (6-6-1) is embedded at one end of the arc-shaped connecting part (6-6-2), and the other end of the arc-shaped connecting part (6-6-2) is embedded in the endoscope hole of the end (6-4).

7. The multi-degree-of-freedom gastrointestinal surgical robot system according to claim 5, characterized in that, The inverse kinematics calculation includes the following: establishing a geometric and kinematic model, simplifying the unfolding mechanism using a piecewise constant curvature model, assuming that each rotary joint of the unfolding mechanism maintains a constant curvature during movement, establishing a coordinate system at each rotary joint of the snake tube, and establishing a base coordinate system at the curved endoscope. Derive the transformation matrix; based on geometric relationships, derive the first... i The coordinate system of the rotational joint is to i +1 homogeneous transformation matrix of the coordinate system of the rotation joints i ∈ N , N Given the total number of rotary joints, the global transformation matrix from the base coordinate system to the force-sensitive elastic body clamping unit is further obtained. A kinematic model is established using the global exponential product method based on spinor theory, representing the motion of each rotary joint as an exponential transformation along a helical axis. The pose of the end rotary joint of the snake tube is obtained by multiplying the transformations of all rotary joints. Inverse kinematics is solved, and based on the constant curvature assumption and geometric relationships, the bending motion of the snake tube is decomposed into the superposition of pitch and yaw rotary joints. The required rotation angle of each pitch and yaw rotary joint is calculated, and a mathematical relationship is established between the rotation angle and the length change of the four sub-arm drive guidewires of the snake tube, realizing the correlation between the operation command and the actual action of the deployment mechanism.

8. The multi-degree-of-freedom gastrointestinal surgical robot system according to claim 7, characterized in that, The realization of clamping force and three-dimensional force sensing includes the following: Based on the structure of the force-sensitive elastomer clamping unit, a four-channel fiber optic force sensor is formed by four hollow beams and four corresponding surface-metallized fiber optic gratings inside; a mathematical relationship is established between the external force and the microscopic deformation of the hollow beam where each fiber optic grating is located; according to the principle of fiber optic gratings, a relationship between wavelength drift and fiber optic grating strain is established, and the real-time wavelength drift is obtained; a mapping relationship between wavelength drift and three-dimensional force is established, and finally, the calculated three-dimensional force and clamping force are output.

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