Four-degree-of-freedom micro surgical robot with remote center of motion and control system

Abstract

Disclosed are a four-degree-of-freedom micro surgical robot with a remote center of motion and a control system. The surgical robot comprises a movable platform mechanism and at least two branch-chain mechanisms that are formed by means of planar processing of a composite layered material. The movable platform mechanism comprises a central connecting rod with a polygonal plane and branch-chain connecting rods connected to side edges of the central connecting rod by means of hinges. The central connecting rod serves as a movable platform for installing surgical instruments. Both the number of the branch-chain connecting rods and the number of sides of the polygon are not smaller than the number of the branch-chain mechanisms. All the branch-chain mechanisms are in the same form, and each of the branch-chain mechanisms is formed by splicing an upper branch chain and a lower branch chain. The four-degree-of-freedom micro surgical machine can meet the requirements of high-degree-of-freedom, high-precision, and large-range operations, reduce the size, weight, and manufacturing costs of a micro operation device, and achieve a complex four-degree-of-freedom operation of rotation and in-situ translation, and has a ten-micrometer-level operation precision and a ten-cubic-centimeter-level operation space.

Description

Four-degree-of-freedom micro-surgical robot with distal motion center and control system Technical Field

[0001] The present invention belongs to the field of micro surgical robots, and in particular relates to a four-degree-of-freedom micro surgical robot with a distal motion center. Background Art

[0002] Surgical robots offer advantages such as improved operational precision and the elimination of hand tremors, contributing to enhanced outcomes in minimally invasive surgery. Minimally invasive surgery is characterized by limited operating space, high precision requirements, high degree of dexterity, and precise force / displacement control. For example, ophthalmic surgery requires precision of 10 microns. Any accidental damage to ocular tissue can result in irreversible consequences, placing extremely high demands on the stability and precision of the surgeon's hands. Therefore, ophthalmic surgery is one of the most challenging procedures in minimally invasive surgery. Human hands have inherent limitations in dexterity, tremor control, and positioning accuracy. Furthermore, traditional manual minimally invasive surgical procedures are subject to long training cycles and numerous postoperative complications. Therefore, the development of surgical robots to assist and replace humans in minimally invasive contact surgery holds significant clinical value and has broad application prospects.

[0003] The remote center of motion (RCM) is a key concept in robotic surgery. It refers to the fixed point in space around which surgical instruments rotate. This point is typically located at or near the instrument's entry point into the patient's body, making RCM ideal for minimally invasive surgery. The RCM concept, when applied to the design of robotic surgical systems, provides high precision, stability, and safety.

[0004] Micro-surgical robots are a new type of robotic technology, generally referring to robots less than 5cm in size used to perform surgical tasks. These robots are characterized by small size, light weight, flexible movements, high operational precision, and ease of integration. Compared to large surgical robots, micro-surgical robots have higher precision and better responsiveness. Taking ophthalmic surgery as an example, micro-surgical robots can overcome the many difficulties of intraocular contact operations, greatly assist doctors in the surgical treatment process, reduce the difficulty of surgical operation training, improve treatment effects, and reduce postoperative complications. Due to the limitations of scale requirements, traditional methods cannot achieve the design and manufacture of micro-robots. Currently, micro-robots are generally designed and manufactured using planar methods.

[0005] Planar processing refers to processing methods for flat materials, including but not limited to additive manufacturing methods such as 3D printing, printing, spraying, extrusion, and chemical synthesis, and subtractive manufacturing methods such as cutting, wire cutting, laser ablation, photolithography, and chemical etching. Planar materials, on the other hand, are materials whose thickness is significantly smaller (by at least one order of magnitude) than their length and width. These include but are not limited to hard flat materials such as metal sheets, plastic sheets, wood boards, and carbon fiber boards, as well as soft flat materials such as polymer films, gel layers, textile fabrics, and metal foils.

[0006] Traditional micro-surgical robots, limited by their design and manufacturing processes, struggle to compress to the centimeter scale and achieve micron-level precision. While existing surgical robotic systems can achieve micron-level precision, they are still bulky relative to their operating range, difficult to deploy, and expensive. Furthermore, no micro-surgical robotic system currently offers both RCM and in-situ puncture capabilities.

[0007] Summary of the Invention

[0008] The purpose of the present invention is to solve the defects of micro surgical robots in the existing technology in terms of operating accuracy and operating range, and to provide a four-degree-of-freedom micro surgical machine with a distal motion center, so as to meet the needs of high degree of freedom, high-precision operation, and large-range operation, reduce the volume, weight and manufacturing cost of micro operating equipment, and realize four-degree-of-freedom operation of rotation and in-situ translation, while having an operating accuracy of 10 microns and an operating space of ten cubic centimeters.

[0009] It should be noted that the concept of degree of freedom in the present invention refers to the movement that the robotic moving platform and the surgical actuator on it can perform in space. In the three-dimensional space described by the Cartesian coordinate system (OXYZ), a rigid body has a maximum of six degrees of freedom, namely, translation along the X, Y, and Z axes and rotation around the X, Y, and Z axes. The four degrees of freedom of the micro-surgical robot moving platform proposed in the present invention refer to the ability to rotate around the X, Y, and Z axes and the ability to translate around the Z axis.

[0010] The specific technical solutions adopted in the present invention are as follows:

[0011] In a first aspect, the present invention provides a four-degree-of-freedom micro-surgical robot with a distal motion center, comprising a moving platform mechanism formed by plane processing of a composite layered material and at least two branch chain mechanisms;

[0012] The movable platform mechanism includes a central connecting rod with a polygonal plane and branch connecting rods connected to the side of the central connecting rod by hinges. The central connecting rod serves as a movable platform for mounting surgical instruments. The number of branch connecting rods and the number of sides of the polygon are not less than the number of branch mechanisms.

[0013] Each branch chain has the same structure, and is composed of an upper branch chain and a lower branch chain.

[0014] The lower branch chain is composed of an integrated sixth link and a seventh link. The sixth link includes a main section and a protruding section. The main section is continuously composed of a first straight section, a circular section, and a second straight section of equal width. The seventh link is fixedly connected to the outer end of the first straight section or rotatably connected via a fifth hinge. The protruding section is arranged on the outer ring side of the main section and is provided with a mounting hole for connecting to an external drive mechanism. The straight line on the side of the second straight section away from the circular section serves as the central axis of rotation when the lower branch chain is driven.

[0015] The upper branch chain is composed of an integrated tenth link, an eleventh link, a twelfth link, and a thirteenth link; the tenth link is fixedly connected to one end of the eleventh link or is rotatably connected via a sixth hinge, the other end of the eleventh link is rotatably connected to one end of the twelfth link via a seventh hinge, the other end of the twelfth link is rotatably connected to the thirteenth link via an eighth hinge, and the thirteenth link is fixedly spliced ​​to the corresponding branch link on the movable platform mechanism via male and female connectors;

[0016] The lower branch chain and the upper branch chain are fixedly spliced ​​by a set of male and female heads respectively provided on the seventh connecting rod and the tenth connecting rod;

[0017] All branch chain mechanisms assembled on the central link satisfy the following five constraints:

[0018] The first constraint is that each branch mechanism must have at least one of the fifth and sixth hinges. If both exist, their hinge axes must coincide.

[0019] The second constraint is that the axes of the seventh hinge and the eighth hinge of each branch mechanism are perpendicular to each other;

[0020] The third constraint is that the second posture angle and the third posture angle of each branch mechanism are less than 180°;

[0021] The fourth constraint is that the eighth hinge in each branch mechanism is parallel to the hinge on the moving platform connected to the current branch mechanism;

[0022] The fifth constraint is that the first and second centers of all branched mechanisms coincide with the same point;

[0023] In each branch mechanism, the existing fifth hinge or sixth hinge is the designated hinge, the intersection of the designated hinge and the rotation center axis is the first center of the circle, the intersection of the designated hinge and the seventh hinge is the second center of the circle, the angle between the designated hinge and the rotation center axis is the second posture angle, and the angle between the designated hinge and the seventh hinge is the third posture angle.

[0024] As a preferred embodiment of the first aspect above, in the moving platform mechanism, the central link is a rectangular fifth link, and there are four branch links connected to the fifth link, namely the first link, the second link, the third link, and the fourth link, and one end of the first link, the second link, the third link, and the fourth link are respectively rotatably connected to the fifth link through the first hinge, the second hinge, the third hinge, and the fourth hinge, and the other ends are respectively fixedly connected to the first branch mechanism, the second branch mechanism, the third branch mechanism, and the fourth branch mechanism by splicing male and female heads; the first hinge and the third hinge are parallel to each other, the second hinge and the fourth hinge are parallel to each other, and the first hinge and the second hinge are perpendicular to each other;

[0025] In the moving platform mechanism and the four branch chain mechanisms connected to the moving platform mechanism, the combination of the first connecting rod and the first branch chain mechanism and the combination of the third connecting rod and the third branch chain mechanism are symmetrically distributed on both sides of the moving platform, while the combination of the second connecting rod and the second branch chain mechanism and the combination of the fourth connecting rod and the fourth branch chain mechanism are symmetrically distributed on both sides of the moving platform.

[0026] As a preferred embodiment of the first aspect, the robot body mounted on the four rotation drive mechanisms satisfies the following four constraints:

[0027] The first constraint is that the equivalent radii of the lower and upper branches of the four branched chain mechanisms are the same;

[0028] The second constraint is: the second posture angle, third posture angle, first hinge distance, and second hinge distance of the first branch mechanism are the same as those of the third branch mechanism; the second posture angle, third posture angle, first hinge distance, and second hinge distance of the second branch mechanism are the same as those of the fourth branch mechanism;

[0029] The third constraint is that the first hinge spacing and the second hinge spacing of each of the four branched chain mechanisms are 0.2 to 2 times the equivalent radius;

[0030] The fourth constraint is that the second posture angle and the third posture angle of each of the four branch chain mechanisms are less than 90°;

[0031] In each branch mechanism, the distance from the first center of the circle to the farthest end of the designated hinge or the distance from the first center of the circle to the farthest end of the side of the second straight segment away from the circular segment is the equivalent radius of the lower branch, the distance from the second center of the circle to the eighth hinge is the equivalent radius of the upper branch, the angle between the rotation center axis and the horizontal plane is the first attitude angle, the distance from the eighth hinge to the hinge connected to the current branch mechanism on the moving platform is the first hinge spacing, and the second hinge spacing is half the distance from the hinge connected to the current branch mechanism on the moving platform to the symmetrical hinge.

[0032] As a preferred embodiment of the above-mentioned first aspect, all connecting rods of the four-degree-of-freedom micro surgical robot are made of composite layered materials, the middle layer of the composite layered material is a flexible planar material layer, and the two sides of the middle layer are hard planar material layers. The flexible planar material layer and the hard planar material layer are bonded and fixed by an adhesive material layer, and the two adjacent connecting rods keep the flexible planar material layer continuous while the hard planar material layer is disconnected at the hinge position, and the edges of the hard planar material layers on both sides of the disconnection position are separated by rectangular grooves and the serrated edges formed by the rectangular grooves are interlocked with each other, so that they can rotate freely around the hinge under the connecting action of the flexible planar material layer.

[0033] As a preferred embodiment of the first aspect above, the flexible planar material layer is a soft polymer film, a soft gel layer, a soft textile cloth, or a soft metal foil; the hard planar material layer is a hard metal plate, a hard plastic plate, a hard glass plate, a hard resin plate, a hard wood plate, or a hard composite material plate.

[0034] As a preferred embodiment of the first aspect above, in the branch chain mechanism, the male and female heads connecting the two connecting rods are separately provided on the two connecting rods, the male head of one connecting rod is assembled to the female head of the other connecting rod, and the two connecting rods are fixed by glue to be connected as one.

[0035] In a second aspect, the present invention provides a four-degree-of-freedom micro-surgical robot control system with a distal motion center, comprising the four-degree-of-freedom micro-surgical robot described in any one of the first aspects above and at least four independent rotation drive mechanisms;

[0036] Each of the branch mechanisms is equipped with a rotation drive mechanism fixed to a base on its lower branch, for driving the branch mechanism to rotate around the corresponding rotation center axis; if the number of rotation drive mechanisms is greater than the number of branch mechanisms, the remaining rotation drive mechanisms are installed on the upper branches of different branch mechanisms, for driving the branch mechanisms to rotate around the corresponding seventh hinge;

[0037] When each branch chain mechanism is assembled with the rotary drive mechanism, the angle between the rotation center axis and the horizontal plane is taken as the first posture angle, and the first posture angle of each branch chain mechanism is less than 90°.

[0038] As a preferred embodiment of the second aspect, the number of the branch chain mechanisms and the number of the rotary drive mechanisms are both four, and the rotary drive mechanisms and the branch chain mechanisms form a one-to-one driving relationship; preferably, the first posture angles of the four branch chain mechanisms are the same.

[0039] As a preferred embodiment of the above-mentioned second aspect, each of the rotary drive mechanisms includes a drive motor and a transmission plate, the transmission plate is mounted on the drive shaft of the drive motor and the plate surface is perpendicular to the drive shaft, and a boss structure is provided on the transmission plate to provide a mounting plane for the protruding section of the sixth connecting rod; preferably, the drive motor is a micro servo motor.

[0040] As a preferred embodiment of the second aspect, a mounting hole is provided at the center of the fifth connecting rod serving as the moving platform, and surgical instruments are mounted through the mounting hole; preferably, the surgical instruments include one or more of a blade, a miniature camera, an injection needle, a lens or a suction cup.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1) The present invention provides a four-degree-of-freedom micro-surgical robot with a distal motion center, which has a volume of less than 80 cubic centimeters, can achieve a repeatability accuracy of 10 microns, a working space of 10 cubic centimeters, has RCM function, and has 4-degree-of-freedom motion capability (including 3 rotational degrees of freedom and one translational degree of freedom), and can perform in situ puncture.

[0043] 2) The four-degree-of-freedom micro surgical robot of the present invention can be produced using intelligent composite materials and planar processing and manufacturing methods, with simple processing technology and low manufacturing cost.

[0044] 3) The robot of the present invention has high surgical adaptability and can replace the operating head according to different surgical requirements to achieve tasks such as cutting and puncture, and has strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a schematic diagram of the theoretical model of a four-degree-of-freedom micro-surgical robot.

[0046] Figure 2 is a plan view of the dynamic platform.

[0047] FIG3 is a planar design diagram of the lower branches of branch A and branch C. FIG3 is a planar design diagram of the lower branches of branch A and branch C.

[0048] FIG4 is a planar design diagram of the lower branches of branches B and D. FIG4 is a planar design diagram of the lower branches of branches B and D.

[0049] FIG5 is a planar design diagram of the upper branches of branch A and branch C. FIG5 is a planar design diagram of the upper branches of branch A and branch C.

[0050] FIG6 is a plan view of the upper branches of branch B and branch D. FIG6 is a plan view of the upper branches of branch B and branch D.

[0051] FIG7 is a schematic diagram of a rectangular slot opening using a moving platform as an example.

[0052] Figure 8 is a plan view of the dynamic platform with island chain and upper branch chain.

[0053] Figure 9 is a plan view of the lower branch with island chains.

[0054] Figure 10 is a design drawing of the nine parts required to produce a four-degree-of-freedom micro surgical robot.

[0055] Figure 11 is a production and processing drawing of a four-degree-of-freedom micro surgical robot.

[0056] Figure 12 is a flowchart of the actual production and assembly of a four-degree-of-freedom micro surgical robot.

[0057] FIG13 is a schematic diagram of the micro surgical robot and its drive transmission system.

[0058] FIG14 is a schematic diagram of the degrees of freedom of motion of the micro robot dynamic platform.

[0059] FIG15 is a schematic diagram of a micro-robot moving platform carrying three instruments: a blade, a micro-camera, and an injection needle.

[0060] FIG16 is a schematic diagram of a micro surgical robot having two branch chain mechanisms and four motors and its drive transmission system.

[0061] FIG17 is a schematic diagram of a micro surgical robot having three branch chain mechanisms and four motors and its drive transmission system.

[0062] FIG18 is a schematic diagram of a micro surgical robot having five branch chain mechanisms and five motors and its drive transmission system.

[0063] FIG19 is a comparison of the fifth hinge and the sixth hinge on the branch mechanism with the default form. DETAILED DESCRIPTION

[0064] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. 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 violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. The technical features in the various embodiments of the present invention can be combined accordingly without conflicting with each other.

[0065] In the description of the present invention, it should be understood that the terms "first" and "second" are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly specifying the number of technical features being described. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one of such features.

[0066] In order to meet the requirements of high degree of freedom, high-precision operation, and large-scale operation, reduce the volume, weight and manufacturing cost of micro-operation equipment, realize four-degree-of-freedom operation of rotation and in-situ translation, and have an operation accuracy of 10 microns and an operation space of ten cubic centimeters, the present invention provides a four-degree-of-freedom micro-surgical robot with a distal motion center. The concept of degree of freedom in the present invention refers to the movement that the robot moving platform and the surgical actuator thereon can perform in space. In the three-dimensional space described by the Cartesian coordinate system (OXYZ), a rigid body has a maximum of six degrees of freedom, namely, translation along the three axes of X, Y, and Z and rotation around the three axes of X, Y, and Z. The four degrees of freedom of the micro-surgical robot moving platform proposed in the present invention refer to the ability to rotate around the three axes of X, Y, and Z and the ability to translate around the Z axis.

[0067] The four-degree-of-freedom microsurgical robot with a distal center of motion provided herein comprises a moving platform structure fabricated from a planar composite layer of material and at least two branching mechanisms. While the robot configuration differs depending on the number of branching mechanisms, the actuation principles of the robot remain essentially the same. Therefore, the following description will focus on the most commonly used four-branch mechanism configuration.

[0068] In a preferred embodiment of the present invention, a theoretical model of a four-degree-of-freedom micro-surgical robot with four branch mechanisms is provided as shown in Figure 1. The mechanism consists of a fixed platform, a moving platform and four branch mechanisms, and each branch mechanism contains three connecting rods. O represents the center of the fixed platform, O' represents the center of the moving platform, A, B, C, and D represent the four branch mechanisms respectively, and the geometric relationship of the mechanism is illustrated by marking the branch mechanism A in the figure, and the other branch mechanisms are the same. In the figure, the fixed platform is labeled 01, the moving platform is labeled 05, and the three connecting rods of the branch mechanism A starting from the fixed platform to the moving platform are labeled 02, 03, and 04 respectively. Part 01 is connected to part 02 by a revolute pair, part 02 is connected to part 03 by a revolute pair, part 03 is connected to part 04 by a universal joint pair, and part 04 is connected to part 05 by a revolute pair. If the universal joint pair is regarded as two rotation pairs, then a branch mechanism of the mechanism contains a total of 5 rotation pairs, and the axes of these rotation pairs from the fixed platform to the moving platform are S1, S2, S3, S4, and S5 respectively. The geometric relationship of the branch mechanism is: the lengths OA1, OA2, OA3, and OA4 are equal to R; the angle between S1 and the horizontal plane is α1; the angle between S1 and S2 is α2; the angle between S2 and S3 is α3; S3 and S4 are perpendicular, and they can intersect or not. For the convenience of manufacturing, S3 and S4 intersect at point A3 (4) in the present invention; S4 and S5 are always parallel; the length of A3 (4) A5 is L1; the distance between A5O' is L2. The projection of the axis S1 of the rotation pair of each branch mechanism on the ground can obtain a straight line. The direction away from point O along this straight line is defined as the distribution direction of this branch mechanism, the vector along this direction is the distribution vector of the branch mechanism, and the angle between the distribution vectors of adjacent branch mechanisms is the distribution angle. The distribution angles of the four branched chain mechanisms of the robot can be arbitrarily set on the premise that the branched chain mechanisms do not interfere with each other. In the present invention, the distribution angles are preferably 90° and will not be discussed as mechanism parameters later.

[0069] In the microsurgical robot constructed using the aforementioned geometric relationships, a line perpendicular to the moving platform through point O' always passes through point O, which is an RCM point in the mechanism. In actual production, to ensure that the actuator mounted on the moving platform is not constrained by the fixed platform, the following example does not use smart composite materials to constrain the positions of points O, A1, B1, C1, and D1. Instead, a metal base is used to constrain the spatial positions of axes OA1, OB1, OC1, and OD1, ensuring they intersect at point O. This will be demonstrated later.

[0070] Based on the theoretical model described above, in a preferred embodiment of the present invention, intelligent composite layered materials and planar machining processes are utilized to materialize the robot, resulting in the design of a four-degree-of-freedom micro-surgical robot with a distal center of motion. This robot's structure comprises a dynamic platform mechanism fabricated from a planar composite layered material and four branched mechanisms also fabricated from the same material. The specific implementation of this mechanism is described in detail below, with reference to Figures 2 to 14.

[0071] The surgical robot comprises a first branch mechanism, a second branch mechanism, a third branch mechanism, and a fourth branch mechanism, which correspond to the four branch mechanisms A, B, C, and D in the theoretical model. The movable platform mechanism comprises a first connecting rod 1, a second connecting rod 2, a third connecting rod 3, a fourth connecting rod 4, and a fifth connecting rod 5, which are integrally formed. The fifth connecting rod 5 serves as a movable platform, the center of which can accommodate surgical instruments. The first connecting rod 1, the second connecting rod 2, the third connecting rod 3, and the fourth connecting rod 4 are rotatably connected to the fifth connecting rod 5 via a first hinge, a second hinge, a third hinge, and a fourth hinge, respectively, at one end. The other ends are fixedly connected to the first branch mechanism, the second branch mechanism, the third branch mechanism, and the fourth branch mechanism via male and female connectors. In this embodiment, the first hinge and the third hinge are parallel to each other, the second hinge and the fourth hinge are parallel to each other, and the first hinge and the second hinge are perpendicular to each other.

[0072] The first, second, third, and fourth branch chains are identical in form, and are all formed by joining an upper branch chain and a lower branch chain. The following uses one of these branch chains as an example to illustrate the specific forms of the upper and lower branches.

[0073] In an embodiment of the present invention, the lower branch chain is composed of a sixth link 6 and a seventh link 7 that are integrally formed. The sixth link 6 includes a main body section and a protruding section. The main body section is continuously composed of a first straight bar section, a circular ring section and a second straight bar section of equal width. The seventh link 7 is rotatably connected to the outer end of the first straight bar section through a fifth hinge. The protruding section is arranged on the outer ring side of the main body section and is provided with a mounting hole for connecting to an external driving mechanism; and one side side of the protruding section is collinear with one side side of the second straight bar section, and the two constitute the central axis of rotation when the lower branch chain is driven.

[0074] In an embodiment of the present invention, the upper branch chain is composed of an integrated tenth link 10, an eleventh link 11, a twelfth link 12 and a thirteenth link 13; the tenth link 10 and one end of the eleventh link 11 are rotatably connected through the sixth hinge, the other end of the eleventh link 11 and one end of the twelfth link 12 are rotatably connected through the seventh hinge, the other end of the twelfth link 12 and the thirteenth link 13 are rotatably connected through the eighth hinge, and the thirteenth link 13 is connected to the corresponding link on the moving platform mechanism, and the axes of the seventh hinge and the eighth hinge are perpendicular to each other.

[0075] In an embodiment of the present invention, the lower branch chain and the upper branch chain are fixedly spliced ​​by a set of male and female heads respectively provided on the seventh connecting rod 7 and the tenth connecting rod 10.

[0076] In an embodiment of the present invention, in order to facilitate installation and driving, in the above-mentioned four-degree-of-freedom micro-surgical robot with a distal motion center, in the moving platform mechanism and the four branch mechanisms connected to the moving platform mechanism, the combination of the first link 1 and the first branch mechanism and the combination of the third link 3 and the third branch mechanism are symmetrically distributed on both sides of the moving platform, while the combination of the second link 2 and the second branch mechanism and the combination of the fourth link 4 and the fourth branch mechanism are symmetrically distributed on both sides of the moving platform. In the above-mentioned four-degree-of-freedom micro-surgical robot, the four branch mechanisms need to be driven by four independent rotation drive mechanisms respectively, rotating around the rotation center axis of their respective lower branches. The specific driving method will be explained in detail later and will not be described in detail here.

[0077] In an embodiment of the present invention, all connecting rods comprising the robot body are fabricated from a composite layered material. The composite layered material comprises a flexible planar material layer in the middle, flanked by hard planar material layers on either side. The flexible and hard planar material layers are bonded together by adhesive layers. At the hinge position, the flexible planar material layer of two adjacent connecting rods remains continuous while the hard planar material layer is disconnected. Furthermore, the edges of the hard planar material layers on either side of the disconnection are spaced apart by rectangular grooves, and the serrated edges formed by the rectangular grooves engage with each other, enabling the connecting rods to freely rotate about the hinge under the coupling action of the flexible planar material layers.

[0078] The composite layered material of the present invention can be formed into a multi-layer composite planar structure in the form of an intelligent composite material by planarizing the planar material and combining it with a bonding manufacturing process. In this composite layered material, the middle layer is a flexible planar material layer, and the outermost two sides are hard planar material layers. The flexible planar material layer and the hard planar material layer are fixed by an adhesive material layer. The hard planar material includes but is not limited to: hard metal plates, hard plastic plates, hard glass plates, hard resin plates, hard wood plates, hard composite material plates (such as hard carbon fiber plates), etc., and the flexible planar material includes but is not limited to: flexible polymer films, flexible gel layers, flexible textile fabrics, flexible metal foils, etc. The adhesive material layer can be in the form of viscose, glue, or hot-pressed tape. After the composite layered material is planarized, the hard planar material layer in the intelligent composite material sandwiches the flexible planar material layer. The hard planar material layers on both sides can be linearly disconnected at the hinge position, while the flexible planar material layer in the middle remains continuous, at this time forming a linear rotation axis, namely the aforementioned hinge. This linear axis of rotation is a straight-line rotating mechanism connected by a flexible planar material layer. The hard planar material layers on either side, after being planarized and separated, can be rotated along the linear axis, thereby achieving the degree of freedom required for the robot hinge. The hard planar material layers on each side of the flexible planar material layer are interlocked with serrations at the hinge location, allowing them to rotate freely around the hinge thanks to the connection of the flexible planar material layers.

[0079] The connecting rod components formed based on this intelligent composite material can be further designed in three dimensions according to the needs, thereby realizing different actuation functions.

[0080] Based on the branched chain structure formed by the planar processing described above, when the two connecting rods need to be connected, a corresponding set of male and female connectors can be installed at the connection position. The position of the male and female connectors can be adjusted as needed. The male and female connectors connecting the two connecting rods are located on two connecting rods. The male connector of one connecting rod is assembled onto the female connector of the other connecting rod, and the two connecting rods are connected as a whole by means of glue or other methods.

[0081] Next, we will describe the planar design and production assembly processes for the aforementioned four-degree-of-freedom micro-surgical robot, which is made from intelligent composite materials. The planar design process first determines the robot's geometric characteristics, followed by a supplementary process design based on the planar design to meet the processing requirements of the intelligent composite materials. The intelligent composite material production and assembly process follows the machining drawings generated in the first step, obtaining all the robot's components through machining and bonding of soft and hard sheet materials. The resulting components are then assembled to create the final four-degree-of-freedom micro-surgical robot.

[0082] In an embodiment of the present invention, the planar design process of the four-degree-of-freedom micro surgical robot is as follows:

[0083] The four-degree-of-freedom micro-surgical robot is assembled by plugging together a moving platform and four similarly shaped branch mechanisms. To facilitate processing, the moving platform is connected to each branch mechanism by plugging, and each branch mechanism is also split into two parts and connected by plugging.

[0084] As described in the theoretical model above, to ensure that the mechanism has a large workspace and good transmission performance, the parameters of the face-to-face branch mechanisms are the same, while the parameters of the adjacent branch mechanisms are different. The present invention uses Figures 2, 3, 4, 5, and 6 to represent the above-mentioned parts. The solid lines in the figures are the outlines of the robot parts, the dashed lines are the flexible hinges, and the parts are divided into different connecting rods by the hinges. The dotted lines are auxiliary lines. Figures 2 to 5 each contain two sub-images on the left and right. The left sub-image is used to mark the serial numbers of the feature points, and the right sub-image is used to mark the connecting rod dimensions.

[0085] Figure 2 is a planar design of the dynamic platform mechanism. It comprises five connecting rods, each with a width of W1. The first connecting rod 1 connects the third connecting rod 3 to two identical branch mechanisms, A and C, each with a length of W11. The second connecting rod 2 connects the fourth connecting rod 4 to two identical branch mechanisms, B and D, each with a length of W12. The fifth connecting rod 5 forms the dynamic platform, with holes for mounting various surgical instruments, as described later (Figure 15). The hinge connecting the fifth link 5 to the first link 1 is A51-A52, the hinge connecting the fifth link 5 to the second link 2 is B51-B52, the hinge connecting the fifth link 5 to the third link 3 is C51-C52, and the hinge connecting the fifth link 5 to the fourth link 4 is D51-D52. The distance between hinges A51-A52 and C51-C52 is W13, and the distance between hinges B51-B52 and D51-D52 is W14. In Figure 2, the first link 1, second link 2, third link 3, and fourth link 4 all have female cross-type connectors. The dimensions of the connectors included in these four links and the links described below are the same. The shape of these connectors ensures the assembly accuracy of the two connected links before the adhesive is cured.

[0086] As described above, each branch mechanism is split into two parts and connected by plug-in connection. The upper half of the branch mechanism, which connects to the moving platform mechanism, is called the upper branch, and the lower half of the branch mechanism, which serves as the input terminal and connects to the motor, is called the lower branch. For ease of description, this invention stipulates that the numbers of the points on branch mechanism A, branch mechanism B, branch mechanism C, and branch mechanism D begin with their respective representative letters.

[0087] Figure 3 is a planar design drawing of the lower branches of branch mechanism A and branch mechanism C, and Figure 4 is a planar design drawing of the lower branches of branch mechanism B and branch mechanism D. Most dimensions of Figure 3 and Figure 4 are the same, and the only difference is caused by the different angle values ​​of θ1 and θ2 (here θ1 and θ2 correspond to α2 in the theoretical model), so here only Figure 3 is used to introduce the lower branch.

[0088] In Figure 3, the lower branch chain is composed of the sixth link 6 and the seventh link 7. The sixth link 6 needs to include a main section and a protruding section, and the main section is continuously composed of a first straight section, a circular section, and a second straight section of equal width. Its design method is as follows: starting from the center point O, extend the radius R downward to point A11, take the link width W1 upward from point A11 to obtain point A12, rotate the solid line A11-A12 clockwise around O by an angle θ1 to obtain hinge A211-A212, translate the dotted line A211-A212 to the right along the direction perpendicular to the dotted line O-A212 by a distance L to obtain dotted line A213-A214, and rotate the solid line A11-A12 along the direction perpendicular to the dotted line O -A12 is translated to the left by a distance L to obtain the dot-dash line A13-A14. With O as the center, use a solid arc to connect points A214 and A14. With O as the center, use a dot-dash arc to connect points A213 and A13. Extend W6 downward from point A11 to obtain point A15. Extend point A15 to the left by W3 to obtain point A16. Extend point A16 upward to intersect the arc A213-A11 at point A17. With O as the center, use a solid arc to connect points A213 and A17. Referring to the solid line A15-A16, draw two circular holes with a radius r with a width of W4 and a height of W5 for passing bolts to connect to the motor. The design method for the seventh connecting rod 7 is as follows: Shift the dashed line A211-A212 to the left by a distance W2 along the perpendicular dotted line O-A212 to obtain the solid line A215-A216. Connect points A215 and A211, and A215 and A216 with solid lines, and install a cross-shaped male connector between points A216 and A212. At this point, the design of the lower branch of branch mechanism A is complete. Branch mechanism C is identical to branch mechanism A; the drawing can be replaced with letter A by C. Branch mechanisms B and D are identical, differing only in angle θ from branches A and C. Simply replace parameter θ1 in Figure 3 with θ2 and follow the above design process to obtain Figure 4, the planar design drawing of branches B and D. The letter B in Figure 4 represents branch mechanism B; replacing the letter with D represents branch mechanism D.

[0089] Figure 5 is a planar design drawing of the upper branches of branch mechanism A and branch mechanism C, and Figure 6 is a planar design drawing of the upper branches of branch mechanism B and branch mechanism D. Most dimensions of Figure 5 and Figure 6 are the same, and the only difference is caused by the different angle values ​​of θ3 and θ4 (here θ3 and θ4 correspond to α3 in the theoretical model). Therefore, only Figure 5 is used to introduce the upper branches here.

[0090] In Figure 5, the upper branch chain consists of the tenth link 10, the eleventh link 11, the twelfth link 12, and the thirteenth link 13. The design method for the fourteenth link 13 is as follows: Starting from the center point O, extend the radius R downward to point A4. From point A4, half the link width W1 is moved left and right to form points A41 and A42, respectively. Points A41 and A42 are connected by a dotted line to form a hinge. Points A41 and A42 are translated upward by a distance W11 to form points A43 and A44. Solid lines connect points A41 and A43, A43 and A44, and A43 and A44 to form a male connector. This connector is connected to the first link 1 during assembly.

[0091] The design method for the twelfth connecting rod 12 is as follows: Shift points A41 and A4 downward by a distance L to points A43 and A44, and connect A41 and A43, and A43 and A44, with solid lines. Shift points A41, A4, and A42 downward by W7 to obtain points A33, A31, and A35. Connect points A42 and A35, and A33 and A35, with solid lines. Shift points A33 and A31 upward by W1 to obtain points A34 and A32. Connect points A44 and A32, and A32 and A34, with solid lines. Connect points A31 and A32 with a dashed line, forming a hinge.

[0092] The design method for the eleventh connecting rod 11 is as follows: With point O as the center, rotate point A4 clockwise by θ3 to obtain point A227. From point A227, move a distance W1 in the direction A227-O to obtain point A221. From point A221, move a distance W1 in the direction A227-O to obtain point A222. Connect points A221 and A222 with a dashed line to form a hinge. Translate dashed line A221-A222 rightward by a distance L perpendicular to the dashed-dotted line O-A222 to obtain dashed-dotted line A223-A224. Move point A33 rightward by half the connecting rod width W1 to obtain point A36. Connect points A224 and A34, A223 and A36, and A36 and A33 with solid lines.

[0093] The design method of the tenth connecting rod 10 is as follows: the dotted line A221-A222 is translated to the left by a distance W2 along the vertical dotted line O-A222 to obtain the solid line A225-A226, and the solid line is used to connect point A226 and point A222. There is a female connector between point 225 and point 221. This connector is connected to the seventh connecting rod 7 during assembly. After connection, point A227 coincides with point A211, point A221 coincides with point A212, and point A225 coincides with point A216.

[0094] At this point, the design of the upper branch of branch mechanism A is complete. Branch mechanism C is identical to branch mechanism A; in its drawings, simply replace the letter A with C. Branch mechanisms B and D are identical, differing only in the angle θ. By replacing parameter θ3 in Figure 5 with θ4 and following the above design process, Figure 6 shows the upper branch plan design for branches B and D. The letter B in Figure 6 represents branch mechanism B; replacing it with D represents branch mechanism D.

[0095] The values ​​of the above parameters can be arbitrarily selected under conditions that can achieve processing. In this example, to balance a small robot size, a large workspace, and good transfer efficiency, the preferred parameters are as follows: W1 = 5mm, W11 = 7mm, W12 = 7.5mm, W13 = 6mm, W14 = 8mm, W3 = 10mm, W4 = 5mm, W5 = 3mm, W6 = 8mm, W7 = 7.5mm, L = 2mm, r = 0.9mm, R = 25mm, θ1 = 45°, θ2 = 70°, θ3 = 60°, θ4 = 70°. The theoretical model parameters corresponding to these production parameters are: α2 = 45°, α3 = 60°, L1 = 14mm, L2 = 2.5mm in branches A and C; α2 = 70°, α3 = 70°, L1 = 14mm, L2 = 2.5mm in branches B and D; R = 25mm; α1 = 15 degrees. As previously described, the angle value of α1 is ensured by the connection between the metal base and the fixed platform input link.

[0096] The above description stipulates that the dotted lines in Figures 2 to 6 are flexible hinges. In order to improve the rigidity of the hinge, a rectangular groove must be etched on the rigid material so that the rigid parts can engage with each other when rotating around the flexible hinge. This engagement can improve the rigidity of the hinge. In Figure 7, the above-mentioned rectangular groove is shown by taking the moving platform mechanism as an example, with the length CL and width CW of the groove marked. The length CL of the rectangular groove is determined by the thickness of the rigid material and the rotation angle range of the hinge. The value is within 3 times the thickness of the rigid material, and is generally 1 times the thickness of the rigid material. The width CW of the rectangular groove is determined by the thickness of the rigid material, the hinge length and the processing accuracy. The value is greater than 1 / 3 of the thickness of the rigid material and less than 1 / 3 of the hinge length. In this example, preferably, CL = 0.55mm and CW = 0.2mm.

[0097] As shown in Figures 8 and 9, due to the processing and manufacturing requirements of smart composite materials, the relative positions of all parts of the microrobot must be fixed during the sheet metal processing process to facilitate the subsequent bonding process and ensure processing accuracy. To meet these process requirements, the design drawings need to be supplemented. The design drawings on the left of Figures 8 and 9 add a connection design between the parts and the sheet metal based on Figures 2 to 7, called "island chains." These island chains are separated by pairs of dashed lines in the drawings. After the bonding process is completed, these separations are broken along the dashed lines to free the formed smart composite component from the sheet metal. The white portion of the design drawings on the right of Figures 8 and 9 represents the sheet metal that has been removed, and the shaded area represents the parts remaining after processing. It can be seen that all parts are connected to the sheet metal base through the island chains.

[0098] The length of the dashed line is defined as the island chain length DL, and the spacing between pairs of dashed lines is defined as the island chain width DW. The island chain length DL is determined by the strength and thickness of the rigid material and the geometry of the parts, and is generally greater than 1 / 5 of the length of the connected parts. The island chain width is selected for ease of processing and is generally less than the largest characteristic dimension of the connected parts.

[0099] Figure 10 is a design drawing of the nine parts required to produce a four-degree-of-freedom micro-surgical robot. In the figure, part 20 is the lower branch chain of branch mechanism A, and part 21 is the lower branch chain of branch mechanism C, and the two correspond to Figure 3; part 22 is the lower branch chain of branch mechanism B, and part 23 is the lower branch chain of branch mechanism D, and the two correspond to Figure 4; part 24 is the upper branch chain of branch mechanism A, and part 25 is the upper branch chain of branch mechanism C, and the two correspond to Figure 5; part 26 is the upper branch chain of branch mechanism B, and part 27 is the upper branch chain of branch mechanism D, and the two correspond to Figure 6; part 28 is the robot dynamic platform, corresponding to Figure 2.

[0100] In the embodiment of the present invention, the production and assembly process of each mechanism is as follows:

[0101] Figure 11 shows the production and processing drawings for a four-degree-of-freedom microsurgical robot. Based on Figure 10, the dotted lines used to free the robot from the sheet metal base are hidden. Drawing 29 is used to process the upper rigid and adhesive layers, drawing 30 is used to process the lower rigid and adhesive layers, and drawing 31 is used to process the middle flexible layer. The differences between drawings 29 and 30 lie in the symmetry of the hinge slot about the hinge midline, the enveloping relationship between the male and female heads, and the directional markings on the right. Drawing 31, which provides rotational functionality as the middle layer, lacks the hinge and its rectangular slot, unlike the other two drawings.

[0102] Figure 12 is a flowchart of the actual production and assembly of a four-degree-of-freedom micro surgical robot, where sub-figures a to c are the production process, and sub-figures d and e are the assembly process.

[0103] The production process is as follows: a. Materials 33 and 35 are bonded to materials 32, 34, and 36; b. Material 37 forms a five-layer intelligent composite structure. At this point, all the robot's structural components have been machined and connected to the base plate via an "island chain"; c. Cutting material 37 along the dotted line releases all the components required to assemble the 4DOF micro-surgical robot from the base plate. Material 38 represents the remaining base plate after the components are released. Materials 32 and 33 in sub-figure a correspond to drawing 29 in Figure 11, material 34 corresponds to drawing 31 in Figure 11, and plates 35 and 36 correspond to drawing 30 in Figure 11. This completes the production of all the components for the 4DOF micro-surgical robot.

[0104] The assembly process is as follows: d. Part 39 corresponds to Figure 2 and is the dynamic platform mechanism of the four-degree-of-freedom microsurgical robot. Part 40 corresponds to Figure 5 and is the upper branch of branch mechanism A. Part 41 corresponds to Figure 3 and is the lower branch of branch mechanism A. Part 42 corresponds to Figure 6 and is the upper branch of branch mechanism D. Part 43 corresponds to Figure 4 (with the letter C changed to D) and is the lower branch of branch mechanism D. As shown in sub-figure d, insert the male connectors of parts 40 and 42 into the female connector of part 39, insert the male connector of part 41 into the female connector of part 40, and insert the male connector of part 43 into the female connector of part 42. e. After completing the connection of branch mechanisms A, B, C, and D as shown in sub-figure d, secure the joints with glue and allow it to fully cure. This completes the robot body, and the four-degree-of-freedom microsurgical robot is now assembled. At this time, the spatial position of the robot's fixed platform has not been fixed yet, and it is fixed by a metal base at the back (Figure 13), and then the rotational driving power is input to the four branch chain mechanisms of the robot.

[0105] The power required to control the microsurgical robot is transmitted through the lower branches of the four input chain mechanisms (the sixth link 6 in branches A and C, and the eighth link 8 in branches B and D). By fixing the input link's rotational axis position according to the parameters of the theoretical model, the four input links are controlled by the rotation drive mechanism to achieve four degrees of freedom control of the dynamic platform (fifth link 5) within the microsurgical robot's workspace.

[0106] Therefore, based on the four-degree-of-freedom micro-surgical robot with a distal motion center in the above-mentioned embodiments, a four-degree-of-freedom micro-surgical robot control system with a distal motion center can be further provided. The control system includes the four-degree-of-freedom micro-surgical robot with a distal motion center in the above-mentioned embodiments and four independent rotation drive mechanisms. Each of the branch mechanisms is equipped with a rotation drive mechanism fixed to the base, which is used to drive the branch mechanism to rotate about the corresponding rotation center axis.

[0107] The aforementioned angle control function can be implemented using a variety of commonly used rotary drive mechanisms, depending on the operating conditions and precision requirements, such as piezoelectric ceramic drive, motor drive, linear drive, electromagnetic drive, friction drive, shape memory alloy drive, and flexible material deformation drive. This embodiment utilizes both mechanical and motor drive for demonstration purposes. Each rotary drive mechanism comprises a drive motor and a transmission plate, which is mounted on the drive shaft of the drive motor with its surface perpendicular to the drive shaft. A boss structure on the transmission plate provides a mounting surface for the protruding section of the sixth connecting rod. The following illustrates the specific assembly of this rotary drive mechanism.

[0108] Figure 13 shows the microsurgical robot and its drive transmission system. Sub-Figure a shows the motor and transmission plate assembly. Part 45 is the micro servo motor, part 46 is the transmission plate, and part 47 is bolt #1. The transmission plate has three through-holes for bolt #1 to secure it to the motor, and two bolt holes for connecting it to the microsurgical robot. The transmission plate connects the micro servo motor to the microsurgical robot and ensures that the rotation axis of the robot's input link coincides with the motor's rotation axis, meeting the robot construction requirements of the theoretical model.

[0109] Sub-figure b shows the assembly of the microsurgical robot and the transmission plate. Item 48 is bolt No. 2, and item 49 is the inverted microsurgical robot body. As shown, bolt No. 2 connects the robot to the transmission plate through two through-holes in the input connecting rod. Sub-figure c shows the assembly of the motor and the base. Item 50 is bolt No. 3, and item 51 is the base. The base has four inclined surfaces for securing the motor according to the theoretical model. Each inclined surface has four through-holes, and bolt No. 3 secures the motor to the base through these through-holes, resulting in sub-figure d. Sub-figure d shows the resulting schematic diagram of the assembly process, completing the construction of the four-degree-of-freedom microsurgical robot system. The metal base secures the robot's fixed platform via the motor and transmission plate. At this point, the robot's actual mechanical parameters are consistent with the theoretical model parameters. By controlling the angle of the small servo motor, precise control of the robot's moving platform is achieved, enabling the platform's actuators to achieve their desired tasks.

[0110] Figure 14 shows a schematic diagram of the degrees of freedom of the microrobot's dynamic platform. In the figure, the origin of the earth coordinate system, O, coincides with the robot's RCM point. The x-axis is parallel to the distribution direction of branch mechanism A, and the y-axis is parallel to the distribution direction of branch mechanism D. Point O' is the geometric center of the robot's dynamic platform. Subfigures a through d, respectively, illustrate the microrobot's dynamic platform's rotational degrees of freedom about the x-axis; rotational degrees of freedom about the y-axis; rotational degrees of freedom about the z-axis; and translational degrees of freedom along the z-axis. As can be seen, a line perpendicular to the dynamic platform through point O' always passes through point O, making O an RCM point of the microrobot.

[0111] In addition, in some embodiments of the present invention, by designing the shape of the area on the moving platform (fifth connecting rod 5), the micro-surgical robot can carry different equipment to face various working conditions. For example: blades, micro cameras, injection needles, lenses, suction cups, etc., which can enable the robot to complete various tasks such as cutting, positioning photography, puncture injection, laser control, adsorption grasping, etc. As shown in Figure 15, the present invention cites three implementation examples of blades, micro cameras, and injection needles. In sub-figure a, a micro-surgical robot model with a blade installed for performing a cutting task is listed; in sub-figure b, a micro-surgical robot model with a micro camera installed for performing an imaging task of the surgical environment is listed; in sub-figure c, a micro-surgical robot model with an injection needle installed for performing a puncture task is listed.

[0112] Figures 1 to 14 above illustrate the theoretical model, specific form, and processing method of a four-degree-of-freedom microsurgical robot with four branch mechanisms. However, this is merely a preferred implementation, and the present invention is not limited thereto. The number of branch mechanisms in the present invention can be adjusted based on actual needs, and two or more branch mechanisms are sufficient. The form of the dynamic platform mechanism also needs to be adaptively adjusted based on the number of branch mechanisms. The basic requirements for the dynamic platform mechanism are: it must include a central link with a polygonal planar shape and branch links connected to the sides of the central link via hinges. The central link serves as the dynamic platform for mounting surgical instruments, and the number of branch links and the number of sides of the polygon must be no less than the number of branch mechanisms. Furthermore, because the number of branch mechanisms may not match the number of rotary drive mechanisms, the order for installing all rotary drive mechanisms on each branch mechanism in the above-mentioned four-degree-of-freedom microsurgical robot control system of the present invention is as follows: First, a rotary drive mechanism fixed to a base is assembled on the lower branch of each branch mechanism to drive the branch mechanism to rotate about the corresponding rotational axis. The number of rotary drive mechanisms should generally be equal to the number of chain branches, though it can be greater. However, any excess rotary drive mechanisms may be redundant. However, since the minimum number of chain branches in a robot is two, while the aforementioned embodiment illustrates a case where there are four chain branches, there may also be two, three, or even five or more. In other words, the number of rotary drive mechanisms does not necessarily match the number of chain branches. If there are exactly four chain branches and four rotary drive mechanisms, then as shown in the aforementioned embodiment, a one-to-one correspondence exists between the rotary drive mechanisms and the chain branches, forming a driving relationship. Each lower branch of each chain branch is equipped with a rotary drive mechanism fixed to the base, with the output shaft axis of this rotary drive mechanism aligning with the rotational center axis of the lower branch. However, if the number of rotary drive mechanisms exceeds the number of chain branches, in addition to the rotary drive mechanism fixed to the base on the lower branch of each chain branch, the remaining rotary drive mechanisms must be installed on the upper branches of different chain branches to drive the branch mechanism to rotate about the seventh hinge in that branch mechanism. The rotary drive mechanism installed on the upper branch chain of the branch chain mechanism can move in space along with the rotary drive mechanism as a whole without the need for installation through a base.

[0113] As shown in Figure 16, the left image shows the main body of a four-degree-of-freedom micro-surgical robot with only two branch mechanisms, and the right image shows the four-degree-of-freedom micro-surgical robot control system after the robot is assembled on the base. This four-degree-of-freedom micro-surgical robot control system contains four rotary drive motors, two of which are fixed to the base and are used to drive the two branch mechanisms to rotate around their respective rotational axes. The other two rotary drive motors (marked M in the figure) are installed on the upper branches of the two branch mechanisms and are used to drive the branches to rotate around the seventh hinge of the branch mechanisms.

[0114] As shown in Figure 17, the left image shows the main body of a four-degree-of-freedom micro-surgical robot with only three branch mechanisms, and the right image shows the four-degree-of-freedom micro-surgical robot control system after the robot is assembled on the base. This four-degree-of-freedom micro-surgical robot control system contains four rotary drive motors, three of which are fixed to the base and are used to drive the three branch mechanisms to rotate around their respective rotational axes. The other rotary drive motor, marked M in the figure, is installed on the upper branch of any one of the branch mechanisms and is used to drive the branch mechanism to rotate around the seventh hinge in that branch mechanism.

[0115] As shown in Figure 18, the left image shows the main body of a four-degree-of-freedom micro-surgical robot with six branching mechanisms, and the right image shows the four-degree-of-freedom micro-surgical robot control system after the robot is assembled on the base. This four-degree-of-freedom micro-surgical robot control system has six rotary drive motors fixed to the base, each of which is used to drive the six branching mechanisms to rotate around their respective rotational axes. Of course, in this approach, it is also possible to further increase the rotary drive motors. The additional motors can be installed on the upper branch of any branching mechanism to drive the branch mechanism to rotate around the seventh hinge in that branch mechanism. However, these motors are redundant and can be eliminated.

[0116] In addition, for each branch mechanism in the present invention, the specific form shown in Figures 8 to 11 is only a preferred method in the corresponding embodiment, and the form of the upper branch and the lower branch can also be adjusted or simplified based on the aforementioned preferred embodiment.

[0117] In a variation of the present invention, the fifth hinge and the sixth hinge in each branch mechanism do not need to exist at the same time, and one of them can be selectively omitted. As shown in Figure 19, the four sub-figures in the left column respectively show the situation where the fifth hinge and the sixth hinge are both present in the four connecting rods, while the four sub-figures in the right column respectively show the situation where the fifth hinge or the sixth hinge does not exist in the four connecting rods. If a hinge does not exist, the two corresponding connecting rods on both sides of the hinge need to be connected by a fixed connection. If a hinge exists, the two corresponding connecting rods on both sides of the hinge are connected in a rotating manner through a hinge. However, it should be noted that the two connecting rods here are connected by a fixed connection, which can mean that the two are fixedly connected by splicing methods such as male and female heads, or they can be directly integrated during the processing process, that is, there is no physical seam at the splicing position, and the two connecting rods are actually integrated.

[0118] In addition, as another variation, the side edge of the protruding section of the sixth link does not necessarily have to be colinear with the side edge of the second straight section. When the two are not colinear, the straight line where the side edge of the second straight section is away from the circular section is located serves as the central axis of rotation when the lower branch chain is driven. Therefore, in general, the most basic requirements for each lower branch chain in the present invention are to meet the following requirements: the lower branch chain is composed of an integrated sixth link 6 and a seventh link 7, the sixth link 6 includes a main section and a protruding section, the main section is continuously composed of a first straight section, a circular section, and a second straight section of equal width, the seventh link 7 is fixedly connected to the outer end of the first straight section or is rotatably connected via a fifth hinge, the protruding section is arranged on the outer ring side of the main section and is provided with a mounting hole for connecting to an external drive mechanism; and the straight line where the side edge of the second straight section is away from the circular section is located serves as the central axis of rotation when the lower branch chain is driven. The most basic requirements for each upper branch chain are that the upper branch chain consists of an integrated tenth link 10, eleventh link 11, twelfth link 12, and thirteenth link 13; the tenth link 10 is fixedly connected to one end of the eleventh link 11 or rotatably connected via a sixth hinge; the other end of the eleventh link 11 is rotatably connected to one end of the twelfth link 12 via a seventh hinge; the other end of the twelfth link 12 is rotatably connected to the thirteenth link 13 via an eighth hinge; and the thirteenth link 13 is fixedly connected to the corresponding branch link on the movable platform mechanism via male and female connectors. The lower and upper branches still need to be fixedly connected via a set of male and female connectors provided on the seventh link 7 and the tenth link 10, respectively.

[0119] It should also be noted that in the entire four-degree-of-freedom micro-surgical robot, the parameters of each component need to be reasonably constrained and optimized according to actual needs. According to the aforementioned theoretical model and the above-mentioned geometric relationship, a branch mechanism of the four-degree-of-freedom micro-surgical robot is defined by 6 mechanism parameters, namely: R, α1, α2, α3, L1, L2. In the present invention, R is recorded as the equivalent radius, α1, α2, α3 are recorded as the first posture angle, the second posture angle, and the third posture, respectively, and L1 and L2 are recorded as the first hinge spacing and the second hinge spacing, respectively. For ease of understanding, the specific definitions of the above 6 mechanism parameters in each branch mechanism are given below:

[0120] Since the fifth hinge and the sixth hinge may not all exist, for the convenience of description, the existing fifth hinge or sixth hinge is called the designated hinge (when the fifth hinge or the sixth hinge exists at the same time, the two are overlapped), the intersection of the designated hinge and the rotation center axis is defined as the first center of the circle, the intersection of the designated hinge and the seventh hinge is defined as the second center of the circle, the distance from the first center of the circle to the farthest end of the designated hinge or the distance from the first center of the circle to the farthest end of the side of the second straight segment away from the circular segment is defined as the equivalent radius R of the lower branch, and the second The distance from the center of the circle to the eighth hinge is defined as the equivalent radius R of the upper branch, the angle between the rotation center axis and the horizontal plane is defined as the first posture angle α1, the angle between the designated hinge and the rotation center axis is defined as the second posture angle α2, the angle between the designated hinge and the seventh hinge is defined as the third posture angle α3, the distance from the eighth hinge to the hinge connected to the current branch mechanism on the moving platform is defined as the first hinge spacing L1, and half the distance from the hinge connected to the current branch mechanism on the moving platform to the symmetrical hinge is defined as the second hinge spacing L2.

[0121] For the four-degree-of-freedom micro-surgical robot of the present invention, all branched mechanisms assembled on the central link must satisfy the following five basic constraints:

[0122] The first basic constraint is that each branch mechanism must have at least one of the fifth and sixth hinges. If both exist, their hinge axes must coincide.

[0123] The second basic constraint is that the axes of the seventh and eighth hinges of each branch mechanism are perpendicular to each other;

[0124] The third basic constraint is that the second posture angle α2 and the third posture angle α3 of each branch mechanism are less than 180°;

[0125] The fourth basic constraint is that the eighth hinge in each branch mechanism is parallel to the hinge on the moving platform connected to the current branch mechanism;

[0126] The fifth basic constraint is that the first and second centers of all branched chain mechanisms coincide with the same point.

[0127] The above five basic constraints need to be met for any micro-surgical robot with any number of branches, but for different actual micro-surgical robots, whether other constraints need to be met can be adjusted according to actual conditions. In the embodiment of the present invention, for the micro-surgical robot under the theoretical configuration shown in Figure 1 above, since there are four branched mechanisms, there are a total of 4×6=24 mechanism parameters. In order to ensure that the mechanism has a larger working space and better transmission performance, these mechanism parameters can further meet the following four optimization constraints:

[0128] The first optimization constraint is that the equivalent radius R of the lower and upper branches of the four branched chain mechanisms are the same;

[0129] The second optimization constraint is that the parameters of each pair of branch mechanisms facing each other are identical, i.e., the second posture angle α2, the third posture angle α3, the first hinge distance L1, and the second hinge distance L2 of the first and third branch mechanisms are identical, and the second posture angle α2, the third posture angle α3, the first hinge distance L1, and the second hinge distance L2 of the second and fourth branch mechanisms are also identical.

[0130] The third optimization constraint is: with R as the characteristic dimension of the mechanism, the first hinge spacing L1 and the second hinge spacing L2 of each of the four branched mechanisms are 0.2 to 2 times the equivalent radius R;

[0131] The fourth optimization constraint is that the second posture angle α2 and the third posture angle α3 of each of the four branch chain mechanisms are less than 90°.

[0132] It should be noted that the first posture angle α1 of each branch mechanism is not formed until the robot and drive mechanism are fully assembled, and cannot be constrained before assembly. However, even after the robot and drive mechanism are fully assembled, the first posture angle α1 must still be subject to the second constraint described above. That is, the first posture angle α1 of the first and third branches must be the same, and the first posture angle α1 of the second and fourth branches must also be the same. For the robot with four branches in the aforementioned embodiment, it is best to maintain the same first posture angle α1 for all four branches.

[0133] The embodiment described above is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. A four-degree-of-freedom micro surgical robot with a distal center of motion, characterized in that, it includes a moving platform mechanism processed from a composite laminated material plane and at least two branch chain mechanisms; The moving platform mechanism includes a central connecting rod with a polygonal plane and branch chain connecting rods hinged to the side edges of the central connecting rod. The central connecting rod serves as the moving platform for installing surgical instruments, and the number of branch chain connecting rods and the number of sides of the polygon are not less than the number of branch chain mechanisms; Each branch chain mechanism has the same form and is spliced by an upper branch chain and a lower branch chain; The lower branch chain is composed of an integrated sixth connecting rod (6) and seventh connecting rod (7). The sixth connecting rod (6) includes a main body section and a protruding section. The main body section is continuously composed of a first straight section, a circular ring section, and a second straight section with equal width. The seventh connecting rod (7) is fixedly connected to the outer end of the first straight section or is rotationally connected through a fifth hinge. The protruding section is arranged on the outer ring side of the main body section and is provided with a mounting hole for connecting an external driving mechanism; and the straight line where the side of the second straight section away from the circular ring section is located is used as the rotation center axis when the lower branch chain is driven; The upper branch chain is composed of an integrated tenth connecting rod (10), eleventh connecting rod (11), twelfth connecting rod (12), and thirteenth connecting rod (13); one end of the tenth connecting rod (10) is fixedly connected to the eleventh connecting rod (11) or is rotationally connected through a sixth hinge. The other end of the eleventh connecting rod (11) is rotationally connected to one end of the twelfth connecting rod (12) through a seventh hinge. The other end of the twelfth connecting rod (12) is rotationally connected to the thirteenth connecting rod (13) through an eighth hinge, and the thirteenth connecting rod (13) is fixedly spliced with the corresponding branch chain connecting rod on the moving platform mechanism through male and female connectors; The lower branch chain and the upper branch chain are fixedly spliced through a set of male and female connectors respectively arranged on the seventh connecting rod (7) and the tenth connecting rod (10); All the branch chain mechanisms assembled on the central connecting rod satisfy the following five constraints: The first constraint is that there is at least one fifth hinge and one sixth hinge in each branch chain mechanism. If both exist simultaneously, the hinge axes of the two need to coincide; The second constraint is that the axes of the seventh hinge and the eighth hinge in each branch chain mechanism are perpendicular to each other; The third constraint is that the second attitude angle and the third attitude angle of each branch chain mechanism are less than 180°; The fourth constraint is that the eighth hinge in each branch chain mechanism is parallel to the hinge on the moving platform connected to the current branch chain mechanism; The fifth constraint is that the first center and the second center in all branch chain mechanisms coincide at the same point; In each branch chain mechanism, taking the existing fifth hinge or sixth hinge as the designated hinge, the intersection point of the designated hinge and the rotation center axis is the first center, the intersection point of the designated hinge and the seventh hinge is the second center, the included angle between the designated hinge and the rotation center axis is the second attitude angle, and the included angle between the designated hinge and the seventh hinge is the third attitude angle.

2. The four-degree-of-freedom micro surgical robot with a distal center of motion according to claim 1, characterized in that, In the moving platform mechanism, the central link is the fifth link (5) in the shape of a rectangle. There are four chain linkages connected to the fifth link (5), namely the first link (1), the second link (2), the third link (3), and the fourth link (4). One ends of the first link (1), the second link (2), the third link (3), and the fourth link (4) are respectively rotationally connected to the fifth link (5) through the first hinge, the second hinge, the third hinge, and the fourth hinge, and the other ends are respectively fixedly connected to the first chain mechanism, the second chain mechanism, the third chain mechanism, and the fourth chain mechanism by means of male-female head splicing; the first hinge and the third hinge are parallel to each other, the second hinge and the fourth hinge are parallel to each other, and the first hinge and the second hinge are perpendicular to each other. In the moving platform mechanism and the four chain mechanisms connected to the moving platform mechanism, the combined mechanism of the first link (1) and the first chain mechanism and the combined mechanism of the third link (3) and the third chain mechanism are symmetrically distributed on both sides of the moving platform, while the combined mechanism of the second link (2) and the second chain mechanism and the combined mechanism of the fourth link (4) and the fourth chain mechanism are symmetrically distributed on both sides of the moving platform.

3. The four-degree-of-freedom micro surgical robot with a distal center of motion as described in claim 2, characterized in that, the robot body assembled on the four rotary drive mechanisms satisfies the following four constraints: The first constraint is that the equivalent radii of the lower and upper branches of the four chain mechanisms are the same; The second constraint is that the second attitude angle, the third attitude angle, the first hinge spacing, and the second hinge spacing of the first chain mechanism and the third chain mechanism are the same, and the second attitude angle, the third attitude angle, the first hinge spacing, and the second hinge spacing of the second chain mechanism and the fourth chain mechanism are the same; The third constraint is that the first hinge spacing and the second hinge spacing of each of the four chain mechanisms are 0.2 to 2 times the equivalent radius; The fourth constraint is that the second attitude angle and the third attitude angle of each of the four chain mechanisms are less than 90°; In each chain mechanism, the distance from the first center to the farthest end of the specified hinge or the distance from the first center to the farthest end of the side of the second straight segment away from the circular segment is used as the equivalent radius of the lower branch, the distance from the second center to the eighth hinge is used as the equivalent radius of the upper branch, the angle between the rotation central axis and the horizontal plane is used as the first attitude angle, the distance from the eighth hinge to the hinge on the moving platform connected to the current chain mechanism is used as the first hinge spacing, and half of the distance from the hinge on the moving platform connected to the current chain mechanism to the symmetric hinge is used as the second hinge spacing.

4. The four-degree-of-freedom micro surgical robot with a distal center of motion as described in claim 1, characterized in that, All the linkages of the four-degree-of-freedom micro surgical robot are processed from composite laminated materials. The middle layer of the composite laminated materials is a flexible planar material layer, and the two sides of the middle layer are rigid planar material layers. The flexible planar material layer and the rigid planar material layer are bonded and fixed through an adhesive material layer. And for adjacent two linkages, the flexible planar material layer remains continuous while the rigid planar material layer is disconnected at the hinge position. Rectangular grooves are spacedly arranged at the edges of the rigid planar material layers on both sides of the disconnection position, and the edges in the form of sawteeth formed by the rectangular grooves are mutually engaged, so that it can freely rotate around the hinge under the connection action of the flexible planar material layer.

5. The four-degree-of-freedom micro surgical robot with a distal center of motion according to claim 4, wherein, the flexible planar material layer is a soft polymer film, a soft gel layer, a soft textile cloth, or a soft metal foil; the rigid planar material layer is a rigid metal plate, a rigid plastic plate, a rigid glass plate, a rigid resin plate, a rigid wood board, or a rigid composite material plate.

6. The four-degree-of-freedom micro surgical robot with a distal center of motion according to claim 1, wherein, in the branched chain mechanism, the male and female heads connecting two linkages are respectively arranged on the two linkages. The male head of one linkage is assembled to the female head of the other linkage and fixed by glue to connect the two linkages into one body.

7. A control system for a four-degree-of-freedom micro surgical robot with a distal center of motion, wherein, it includes the four-degree-of-freedom micro surgical robot according to any one of claims 1 to 6 and at least four independent rotary drive mechanisms; wherein a rotary drive mechanism fixed on a base (51) is assembled on the lower branched chain of each branched chain mechanism for driving the branched chain mechanism where it is located to rotate and act around the corresponding rotary central axis; if the number of rotary drive mechanisms is greater than the number of branched chain mechanisms, the remaining rotary drive mechanisms are installed on the upper branched chains of different branched chain mechanisms for driving the branched chain mechanism where it is located to rotate and act around the corresponding seventh hinge; and in the state where each branched chain mechanism is assembled with the rotary drive mechanism, with the included angle between the rotary central axis and the horizontal plane as the first attitude angle, the first attitude angle of each branched chain mechanism is less than 90°.

8. The control system for a four-degree-of-freedom micro surgical robot with a distal center of motion according to claim 7, wherein, the number of both the branched chain mechanisms and the rotary drive mechanisms is four, and the rotary drive mechanisms and the branched chain mechanisms form a driving relationship in one-to-one correspondence; preferably, the first attitude angles of the four branched chain mechanisms are the same.

9. The control system for a four-degree-of-freedom micro surgical robot with a distal center of motion according to claim 7, wherein, each rotary drive mechanism includes a drive motor (45) and a transmission plate (46). The transmission plate (46) is assembled on the drive shaft of the drive motor (45) and the plate surface is perpendicular to the drive shaft. An installation plane for the protruding section of the sixth linkage (6) is provided on the transmission plate (46) through a boss structure; preferably, the drive motor (45) is a micro servo motor.

10. The four-degree-of-freedom micro-surgical robot control system with a distal center of motion as claimed in claim 7, characterized in that, a mounting hole is provided at the center of the fifth link (5) serving as the moving platform, and surgical instruments are mounted through the mounting hole; preferably, the surgical instruments include one or more of a blade, a micro camera, an injection needle, a lens or a suction cup.

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