CN117898835B - Four-degree-of-freedom miniature surgical robot with distal movement center and control system - Google Patents

Abstract

The present invention discloses a four-degree-of-freedom micro-surgical robot and control system with a distal motion center. The surgical robot includes a moving platform mechanism and at least two branch chain mechanisms made of a composite layered material plane; the moving platform mechanism includes a central connecting rod with a polygonal plane and a branch chain connecting rod connected to the side of the central connecting rod by a hinge, the central connecting rod serves as a moving platform for installing surgical equipment, the number of the 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 is the same in form and is spliced by 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 operation, and large-range operation, reduce the volume, weight and manufacturing cost of micro-operating equipment, realize four-degree-of-freedom operation of rotation and in-situ translation, and have an operating accuracy of 10 microns, and the operating space reaches ten cubic centimeters.

Description

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

Technical Field

The 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

Surgical robots have the advantages of improving operation accuracy and eliminating operator hand tremors, which helps to improve the effect of minimally invasive surgery. Minimally invasive surgery has the characteristics of limited operation space, high precision requirements, high flexibility of movement, and high precision of force/displacement process control. Taking ophthalmic surgery as an example, its precision requirement is 10 microns. Any accidental damage to the eye tissue will lead to irreversible consequences, which puts extremely high demands on the stability and precision of the operator's hands. Therefore, ophthalmic surgery is one of the most challenging operations in minimally invasive surgery. Human hands have inherent limitations in dexterity, control over tremors, and positioning accuracy. In addition, the traditional manual minimally invasive surgery process has the disadvantages of long training cycle and many postoperative complications. Therefore, the development of surgical robots to assist and replace humans in completing minimally invasive contact surgery has extremely broad application prospects and important clinical value.

RCM (remote center-of-motion) is an important concept in the field of robotic surgery. It refers to a fixed point in space through which the surgical instrument rotates. This point is usually located at or near the entry point of the surgical instrument into the patient's body, so RCM is very suitable for performing minimally invasive surgery. The concept of RCM can provide high precision, stability and safety when used to design robotic surgical systems.

Micro-surgical robots are a new type of robotic technology, generally referring to robots with a size of less than 5 cm used to perform surgical tasks. Such robots have the characteristics of small size, light weight, flexible movement, high operating precision and easy integration. Micro-surgical robots have higher precision and better responsiveness than large surgical robots. Taking ophthalmic surgery as an example, micro-surgical robots can overcome 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. At present, micro-robots generally adopt planar design and manufacturing methods.

Planar processing refers to the processing methods for flat materials, including but not limited to: additive manufacturing methods such as 3D printing, printing, spraying, extrusion, chemical synthesis, or subtractive manufacturing methods such as cutting, wire cutting, laser ablation, photolithography, chemical etching, etc. Flat materials refer to materials whose thickness is much smaller (at least one order of magnitude) than their length and width, including but not limited to: hard flat materials such as metal sheets, plastic sheets, wood boards, carbon fiber boards, and soft flat materials such as polymer films, gel layers, textile fabrics, and metal foils.

As for micro-surgical robots, traditional surgical robots are limited by their design and manufacturing processes, making it difficult to compress their volume to the centimeter scale and achieve micron-level operating accuracy. Although existing surgical robot systems can achieve micron-level operating accuracy, they still have disadvantages such as large size, difficult deployment, and high price relative to their operating range. At present, there is no micro-surgical robot system that can achieve RCM functions and have in-situ puncture capabilities.

Summary of the invention

The purpose of the present invention is to solve the defects of micro surgical robots in the prior art 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. At the same time, it has an operating accuracy of 10 microns and an operating space of ten cubic centimeters.

It should be noted that the concept of degrees of freedom in the present invention refers to the movements that the robot moving platform and the surgical actuators 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 X, Y, and Z axes and rotation around the X, Y, and Z axes. The four degrees of freedom of the microsurgical 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.

The specific technical solutions adopted by the present invention are as follows:

In a first aspect, the present invention provides a four-degree-of-freedom micro-surgical robot with a distal motion center, which includes a moving platform mechanism made of a composite layered material plane and at least two branch chain mechanisms;

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 connecting rods.

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

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 through 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 driving mechanism; and the straight line where the side of the second straight section away from the circular 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 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 through a sixth hinge, the other end of the eleventh link is rotatably connected to one end of the twelfth link through a seventh hinge, the other end of the twelfth link is rotatably connected to the thirteenth link through an eighth hinge, and the thirteenth link is fixedly spliced with the corresponding branch chain link on the moving platform mechanism through male and female heads;

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

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

The first constraint is that at least one of the fifth hinge and the sixth hinge of each branch mechanism exists. If both exist, the hinge axes of the two hinges must coincide.

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

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

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;

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

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.

As a preferred embodiment of the first aspect, in the moving platform mechanism, the central link is a fifth link in a rectangular shape, and there are four branch links connected to the fifth link, namely, a first link, a second link, a third link, and a 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 a first hinge, a second hinge, a third hinge, and a 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;

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.

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

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

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

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

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°;

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 half distance from the hinge connected to the current branch mechanism on the moving platform to the symmetrical hinge is the second hinge spacing.

As a preferred embodiment of the above-mentioned first aspect, all the 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 flexible planar material layer of two adjacent connecting rods is kept 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 spaced apart 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.

As a preferred embodiment of the above-mentioned first aspect, 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.

As a preferred embodiment of the above-mentioned first aspect, in the branch chain mechanism, the male and female heads connecting the two connecting rods are separately arranged 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.

In a second aspect, the present invention provides a four-degree-of-freedom micro-surgical robot control system with a distal motion center, which comprises 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;

The lower branch chain of each branch chain mechanism is equipped with a rotation drive mechanism fixed on the base, which is used to drive the branch chain mechanism to rotate around the corresponding rotation center axis; if the number of rotation drive mechanisms is greater than the number of branch chain mechanisms, the remaining rotation drive mechanisms are installed on the upper branches of different branch chain mechanisms, which are used to drive the branch chain mechanisms to rotate around the corresponding seventh hinge;

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°.

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

As a preferred embodiment of the above-mentioned second aspect, each of the rotating drive mechanisms includes a driving motor and a transmission plate, the transmission plate is mounted on the driving shaft of the driving motor and the plate surface is perpendicular to the driving 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 driving motor is a micro servo motor.

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.

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

1) The present invention provides a micro surgical robot with four degrees of freedom and 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 an RCM function, and has a four-degree-of-freedom motion capability (including three rotational degrees of freedom and one translational degree of freedom), and can realize in situ puncture.

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.

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

FIG1 is a schematic diagram of a theoretical model of a four-degree-of-freedom micro-surgical robot.

Figure 2 is a plan view of the moving platform.

FIG3 is a plan view of the lower branches of branch A and branch C. FIG.

FIG. 4 is a plan view of the lower branches of branch chain B and branch chain D. FIG.

FIG. 5 is a plan view of the upper branches of branch A and branch C. FIG.

FIG. 6 is a plan view of the upper branches of branch chain B and branch chain D. FIG.

FIG. 7 is a schematic diagram of a rectangular slot opening using a moving platform as an example.

FIG8 is a plan view of the moving platform with an island chain and an upper branch chain.

Figure 9 is a plan view of the lower branch chain with an island chain.

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

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

FIG12 is a flowchart of the actual production and assembly of a four-DOF micro-surgical robot.

FIG. 13 is a schematic diagram of a micro surgical robot and its drive transmission system.

FIG. 14 is a schematic diagram of the degrees of freedom of motion of the micro robot moving platform.

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

FIG. 16 is a schematic diagram of a micro surgical robot having two branch chain mechanisms and four motors and its drive transmission system.

FIG. 17 is a schematic diagram of a micro surgical robot having three branch chain mechanisms and four motors and its drive transmission system.

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

FIG. 19 is a comparison of the fifth hinge and the sixth hinge on the branch chain mechanism with the default form.

DETAILED DESCRIPTION

In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation mode of the present invention is described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from 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 each embodiment of the present invention can be combined accordingly without conflicting with each other.

In the description of the present invention, it should be understood that the terms "first" and "second" are only used for the purpose of distinguishing descriptions, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

In order to meet the requirements of high degree of freedom, high-precision operation, and large-range 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, the operation space reaches ten cubic centimeters, and 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 of the robot moving platform and the surgical actuator thereon 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, which are 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.

The four-degree-of-freedom micro-surgical robot with a distal motion center provided in the present invention comprises a moving platform mechanism made of a composite layered material plane and at least two branch chain mechanisms. Since the robot configurations under different numbers of branch chain mechanisms are different, but the actuation principles of the robots are basically the same, the following first introduces the most commonly used four branch chain mechanisms.

In a preferred embodiment of the present invention, the theoretical model of a four-degree-of-freedom micro-surgical robot with four branched mechanisms is shown in Figure 1. The mechanism consists of a fixed platform, a moving platform and four branched mechanisms, each of which 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 branched mechanisms respectively, and the geometric relationship of the mechanism is illustrated by marking the branched mechanism A in the figure, and the other branched mechanisms are the same. In the figure, the fixed platform is numbered 01, the moving platform is numbered 05, and the three connecting rods of the branched mechanism A from the fixed platform to the moving platform are numbered 02, 03, and 04 respectively. Part 01 is connected to part 02 through a revolute pair, part 02 is connected to part 03 through a revolute pair, part 03 is connected to part 04 through a universal joint pair, and part 04 is connected to part 05 through a revolute pair. If the universal joint pair is regarded as two revolute pairs, then a branch mechanism of the mechanism contains a total of 5 revolute pairs, and the axes of these revolute 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 revolute pair axis S1 of each branch mechanism onto the ground can obtain a straight line. The direction away from point O along the straight line is defined as the distribution direction of the 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 branch chain mechanisms of the robot can be arbitrarily set on the premise that the branch 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 hereinafter.

In the micro-surgical robot constructed by the above geometric relationship, the straight line passing through point O' and perpendicular to the moving platform always passes through point O, which is an RCM point of the mechanism. In actual production, in order to prevent the actuator installed on the moving platform from being restricted by the fixed platform, the following example does not use the smart composite material to constrain the positions of points O, A1, B1, C1 and D1, but uses the metal base to constrain the positions of axes OA1, OB1, OC1 and OD1 in space and ensure that they intersect at point O, which will be demonstrated in the subsequent description.

Based on the above theoretical model, in a preferred embodiment of the present invention, the robot can be materialized by using intelligent composite layered materials and plane processing technology, thereby designing a four-degree-of-freedom micro-surgical robot with a distal motion center, the composition structure of which includes a moving platform mechanism made of composite layered material plane processing and four branched chain mechanisms made of composite layered material plane processing. The specific implementation methods are described in detail below in conjunction with Figures 2 to 14.

Among them, the first branch chain mechanism, the second branch chain mechanism, the third branch chain mechanism and the fourth branch chain mechanism are connected to the moving platform mechanism in the surgical robot, and the first branch chain mechanism, the second branch chain mechanism, the third branch chain mechanism and the fourth branch chain mechanism correspond to the four branch chain mechanisms A, B, C and D in the aforementioned theoretical model respectively. The above-mentioned moving platform mechanism is composed of 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 processed and formed, wherein the fifth connecting rod 5 is used as a moving platform, and the center of which can be installed with surgical equipment. One end of the first connecting rod 1, the second connecting rod 2, the third connecting rod 3 and the fourth connecting rod 4 is respectively connected to the fifth connecting rod 5 by a first hinge, a second hinge, a third hinge and a fourth hinge, and the other end is respectively fixed to the first branch chain mechanism, the second branch chain mechanism, the third branch chain mechanism and the fourth branch chain mechanism by a male and female head splicing method. 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.

The first branch chain mechanism, the second branch chain mechanism, the third branch chain mechanism and the fourth branch chain mechanism are of the same form, and are all formed by splicing an upper branch chain and a lower branch chain. The following takes one of the branch chain mechanisms as an example to illustrate the specific forms of the upper branch chain and the lower branch chain.

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 section and a protruding section. The main section is continuously composed of a first straight section, a circular ring section and a second straight section of equal width. The seventh link 7 is rotatably connected to the outer end of the first straight section through 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 an external driving mechanism; and one side side of the protruding section is colinear with one side side of the second straight section, and the two constitute the central axis of rotation when the lower branch chain is driven.

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 via a sixth hinge, the other end of the eleventh link 11 and one end of the twelfth link 12 are rotatably connected via a seventh hinge, the other end of the twelfth link 12 and the thirteenth link 13 are rotatably connected via an 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.

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 arranged on the seventh connecting rod 7 and the tenth connecting rod 10.

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 chain mechanisms connected to the moving platform mechanism, the combination of the first connecting rod 1 and the first branch chain mechanism and the combination of the third connecting rod 3 and the third branch chain mechanism are symmetrically distributed on both sides of the moving platform, and the combination of the second connecting rod 2 and the second branch chain mechanism and the combination of the fourth connecting rod 4 and the fourth branch chain 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 chain mechanisms need to be driven by four independent rotation drive mechanisms respectively, rotating around the rotation center axis of each lower branch chain. The specific driving method will be described in detail later, and will not be described in detail here.

In the embodiment of the present invention, all the connecting rods constituting the robot body are made of composite layered materials. The middle layer of the composite layered material is a flexible plane material layer, and the two sides of the middle layer are hard plane material layers, and the flexible plane material layer and the hard plane material layer are bonded and fixed by an adhesive material layer, and the two adjacent connecting rods keep the flexible plane material layer continuous and the hard plane material layer disconnected at the hinge position, and the edges of the hard plane material layers on both sides of the disconnection position are spaced apart with rectangular grooves and the sawtooth edges formed by the rectangular grooves are interlocked with each other, so that they can rotate freely around the hinge under the connection of the flexible plane material layer.

The above-mentioned composite layered material in the present invention can be formed into a multi-layer composite plane structure in the form of an intelligent composite material by planarizing the plane material and combining it with the bonding manufacturing process. In the composite layered material, the middle layer is a flexible plane material layer, and the outermost two sides are hard plane material layers, and the flexible plane material layer and the hard plane material layer are fixed by an adhesive material layer. The hard plane material includes but is not limited to: hard metal plate, hard plastic plate, hard glass plate, hard resin plate, hard wood plate, hard composite material plate (such as hard carbon fiber plate), etc., and the flexible plane material includes but is not limited to: flexible polymer film, flexible gel layer, flexible textile cloth, flexible metal foil, etc. The adhesive material layer can be in the form of viscose, glue or hot pressing tape. After the composite layered material is planarized, the hard plane material layer in the intelligent composite material sandwiches the flexible plane material layer, and the hard plane material layers on both sides can be disconnected linearly at the hinge position, while the middle flexible plane material layer remains continuous, and a linear rotation axis, namely the aforementioned hinge, can be formed. The linear rotation axis is a rotation mechanism connected by a flexible planar material layer in a straight line, and the hard planar material layers on both sides can be used to rotate along the linear rotation axis after being planarized and divided, thereby obtaining the degree of freedom of movement and forming the degree of freedom of rotation required by the robot hinge. The hard planar material layers on each side of the flexible planar material layer are serrated at the hinge position, so that they can rotate freely around the hinge under the connection of the flexible planar material layer.

The connecting rod components formed by processing this intelligent composite material can further be designed in three dimensions according to the needs to achieve different actuation functions.

Based on the branched chain mechanism formed by the above-mentioned planar processing, when the two connecting rods need to be connected, a set of corresponding male and female heads can be set at the connection position, and the position distribution of the male and female heads can be adjusted as needed. The male and female heads connecting the two connecting rods are arranged on the two connecting rods, and the male head of one connecting rod is assembled to the female head of the other connecting rod, and the two connecting rods are connected as a whole by means of glue fixation.

Next, the planar design process and production assembly process of the above-mentioned four-degree-of-freedom micro-surgical robot made of intelligent composite materials are described. The planar design process needs to first determine the geometric characteristics of the robot, and then supplement the process design based on the planar design to meet the processing requirements of intelligent composite materials. The production and assembly process of intelligent composite materials is to obtain all the components of the robot through processing and bonding of soft and hard plates according to the processing drawings generated in the first step, and then assemble the components produced to obtain the final four-degree-of-freedom micro-surgical robot.

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

The four-degree-of-freedom micro surgical robot is assembled by plugging one moving platform mechanism and four branch chain mechanisms of similar shapes. In order to facilitate processing, the moving platform mechanism is connected to each branch chain mechanism by plugging, and each branch chain mechanism is also divided into two parts and connected by plugging.

As described in the theoretical model above, in order to ensure that the mechanism has a larger working space and better transmission performance, the parameters of the face-to-face branch chain mechanisms are the same, and the parameters of the adjacent branch chain mechanisms are different. The present invention uses Figures 2, 3, 4, 5 and 6 to represent the above parts. The solid lines in the figures are the contour lines of the robot parts, the dotted lines are the flexible hinges, the parts are divided into different connecting rods by the hinges, and the dotted lines are auxiliary lines. Figures 2 to 5 all contain two left and right sub-images. 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 size.

Figure 2 is a plan view of the moving platform mechanism. The moving platform mechanism includes 5 connecting rods with a width of W1. The first connecting rod 1 and the third connecting rod 3 are connected to two branching mechanisms A and C with the same parameters, and their lengths are both W11; the second connecting rod 2 and the fourth connecting rod 4 are connected to two branching mechanisms B and D with the same parameters, and their lengths are both W12; the fifth connecting rod 5 is a moving platform, on which holes can be opened for installing different surgical instruments, which will be described later (Figure 15). The hinges connecting the fifth connecting rod 5 and the first connecting rod 1 are A51-A52, the hinges connecting the fifth connecting rod 5 and the second connecting rod 2 are B51-B52, the hinges connecting the fifth connecting rod 5 and the third connecting rod 3 are C51-C52, the hinges connecting the fifth connecting rod 5 and the fourth connecting rod 4 are D51-D52, the distance between the hinges A51-A52 and the hinges C51-C52 is W13, and the distance between the hinges B51-B52 and the hinges D51-D52 is W14. In FIG2, the first connecting rod 1, the second connecting rod 2, the third connecting rod 3, and the fourth connecting rod 4 all contain cross plug-in connector female heads, and the sizes of the plug-in connectors contained in these four connecting rods and the connecting rods described later are the same, and the shapes of these connectors can ensure the assembly accuracy of the two connected connecting rods before bonding and curing.

According to the above, each branch mechanism is divided into two parts and connected by plugging. The upper part of the branch mechanism connected to the moving platform mechanism is called the upper branch, and the lower part of the branch mechanism connected to the motor as the input end is called the lower branch. For the convenience of description, the present invention stipulates that the numbers of the points on the branch mechanism A, branch mechanism B, branch mechanism C, and branch mechanism D start with their own representative letters.

FIG3 is a plan design drawing of the lower branch of branch mechanism A and branch mechanism C, and FIG4 is a plan design drawing of the lower branch of branch mechanism B and branch mechanism D. Most dimensions of FIG3 and FIG4 are the same, and the only difference is caused by the different angle values of θ1 and θ2 (θ1 and θ2 here correspond to α2 in the theoretical model), so the lower branch is introduced here only through FIG3.

In FIG3 , 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. The design method is as follows: starting from the center point O, the radius R is extended downward to reach point A11, point A11 is taken upward by the link width W1 to obtain point A12, the solid line A11-A12 is rotated clockwise by an angle θ1 with O as the center to obtain hinge A211-A212, the dotted line A211-A212 is translated to the right by a distance L along the direction perpendicular to the dotted line O-A212 to obtain dotted line A213-A214, the solid line A11-A12 is translated 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, a solid arc is used to connect points A214 and A14. With O as the center, a dot-dash arc is used to connect points A213 and A13. Point A11 is extended downward by W6 to obtain point A15. Point A15 is extended to the left by W3 to obtain point A16. Point A16 is extended upward to intersect the arc A213-A11 at point A17. With O as the center, a solid arc is used to connect points A213 and A17. Referring to the solid line A15-A16, two circular holes with a radius of r are drawn with a width of W4 and a height of W5 for passing bolts to connect to the motor. The design method of the seventh connecting rod 7 is: move the dotted line A211-A212 to the left by a distance W2 along the vertical dotted line O-A212 to obtain the solid line A215-A216, connect point A215 with point A211, point A215 with point A216 with solid lines, and set a cross plug male connector between point A216 and point A212. At this point, the design of the lower branch of the branch mechanism A is completed, and the branch mechanism C is the same as the branch mechanism A. The letter A can be replaced by C in its drawing. The branch mechanisms B and D are the same, and only the angle θ is different from the branch mechanisms A and C. It is only necessary to replace the parameter θ1 in Figure 3 with θ2 and then design according to the above process to obtain Figure 4, that is, the plane design drawing of the branch mechanisms B and D. The letter marked in Figure 4 is B, which represents the branch mechanism B. Replacing the letter with D can represent the branch mechanism D.

FIG5 is a plan design drawing of the upper branches of branch mechanism A and branch mechanism C, and FIG6 is a plan design drawing of the upper branches of branch mechanism B and branch mechanism D. Most dimensions of FIG5 and FIG6 are the same, and the only difference is caused by the different angle values of θ3 and θ4 (θ3 and θ4 here correspond to α3 in the theoretical model), so the upper branches are only introduced here through FIG5.

In FIG5 , the upper branch chain is composed of the tenth link 10, the eleventh link 11, the twelfth link 12 and the thirteenth link 13. The design method of the fourteenth link 13 is as follows: starting from the center point O, the radius R is extended downward to reach point A4, and point A41 and point A42 are obtained by taking half of the link width W1 to the left and right of point A44, respectively. Point A41 and point A42 are connected by a dotted line to form a hinge. Point A41 and point A42 are translated upward by a distance W11 to obtain point A43 and point A44. Point A41 and point A43, point A43 and point A44, and point A43 and point A44 are connected by a solid line to form a male connector, which is connected to the first link 1 during assembly.

The design method of the twelfth connecting rod 12 is as follows: point A41 and point A4 are translated downward by a distance L to point A43 and point A44, and A41 and A43, and A43 and A44 are connected with solid lines. Point A41, A4, and A42 are translated downward by W7 to obtain point A33, point A31, and point A35, and point A42 and point A35 are connected with solid lines. Point A33 and point A31 are translated upward by W1 to obtain point A34 and point A32. Point A44 and point A32, and point A32 and point A34 are connected with solid lines. Point A31 and point A32 are connected with dotted lines to form a hinge.

The design method of the eleventh connecting rod 11 is as follows: with point O as the center of the circle, point A4 is rotated clockwise by θ3 to obtain point A227, point A221 is moved from point A227 along the direction of A227-O by a distance W1, point A222 is moved from point A221 along the direction of A227-O by a distance W1, and point A221 and point A222 are connected by a dotted line to form a hinge. The dotted line A221-A222 is translated to the right by a distance L along the direction of the vertical dotted line O-A222 to obtain the dotted line A223-A224. Point A33 is moved to the right by half the connecting rod width W1 to obtain point A36. Point A224 and point A34, point A223 and point A36, and point A36 and point A33 are connected by solid lines.

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 direction of 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.

At this point, the design of the upper branch of branch mechanism A is completed. Branch mechanism C is the same as branch mechanism A, and its drawing can be replaced by replacing letter A with C. Branch mechanisms B and D are the same, and only differ from branch mechanisms A and C in angle θ. After replacing parameter θ3 in Figure 5 with θ4 and then designing according to the above process, Figure 6 can be obtained, which is the upper branch plane design drawing of branch mechanisms B and D. The letter marked in Figure 6 is B, which represents branch mechanism B. Replacing the letter with D can represent branch mechanism D.

The values of the above parameters can be selected arbitrarily under the condition that the processing can be realized. In this example, in order to take into account the small robot volume, large working space 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 the branching mechanisms A and C; α2 = 70°, α3 = 70°, L1 = 14mm, L2 = 2.5mm in the branching mechanisms B and D; R = 25mm; α1 = 15 degrees. As described previously, the angle value of α1 is ensured by the connection between the metal base and the fixed platform input link.

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, and the length CL of the groove and the width CW of the groove are 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 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, and 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 are taken.

As shown in Figures 8 and 9, due to the processing and manufacturing requirements of smart composite materials, in order to facilitate the subsequent bonding process and ensure processing accuracy, the relative positions of all parts of the microrobot should be fixed during the processing of the plate and cannot be separated from the plate. In order to meet the above process requirements, the design drawings need to be supplemented. The design drawings on the left of Figures 8 and 9 add the connection design between the parts and the plate on the basis of Figures 2 to 7, which is called "island chain". These island chains are separated by pairs of dotted lines in the figure. After the bonding process is completed, these separations can be interrupted along the dotted lines to free the formed smart composite material components from the plate. The white part of the design drawings on the right of Figures 8 and 9 represents the plate that has been removed, and the shaded color represents the remaining parts after processing. It can be seen that all parts are connected to the plate base through island chains.

The length of the dotted line is defined as the length DL of the island chain, and the spacing between the paired dotted lines is defined as the width DW of the island chain. The selection of the island chain length DL is determined by the strength, thickness and geometric dimensions of the rigid material, and is generally greater than 1/5 of the length of the connected parts. The width of the island chain is selected based on the convenience of processing, and is generally smaller than the maximum characteristic size of the connected parts.

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 chain mechanism A, and part 21 is the lower branch chain of branch chain mechanism C, and the two correspond to Figure 3; part 22 is the lower branch chain of branch chain mechanism B, and part 23 is the lower branch chain of branch chain mechanism D, and the two correspond to Figure 4; part 24 is the upper branch chain of branch chain mechanism A, and part 25 is the upper branch chain of branch chain mechanism C, and the two correspond to Figure 5; part 26 is the upper branch chain of branch chain mechanism B, and part 27 is the upper branch chain of branch chain mechanism D, and the two correspond to Figure 6; part 28 is the robot moving platform, corresponding to Figure 2.

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

Figure 11 is a production and processing drawing of a four-degree-of-freedom micro-surgical robot. Based on Figure 10, the dotted line used to free the robot from the plate base is hidden. Among them, Drawing No. 29 is used to process the upper rigid layer material and the upper adhesive layer material, Drawing No. 30 is used for the lower rigid layer material and the upper adhesive layer material, and Drawing No. 31 is used to process the middle flexible layer material. Among the above drawings, the difference between Drawing No. 29 and Drawing No. 30 is that the hinge groove is symmetrical about the hinge midline, the male and female head envelope relationship, and the direction mark on the right. Drawing No. 31 provides a rotation function as an intermediate layer, and compared with the other two drawings, the hinge and its rectangular slot are not drawn.

FIG12 is a flowchart of the actual production and assembly of a four-DOF micro surgical robot, wherein sub-figures a to c are the production process, and sub-figures d and e are the assembly process.

The production process is as follows: a. Use materials 33 and 35 to bond materials 32, 34, and 36; b. Material 37 is a 5-layer intelligent composite structure. At this time, all the parts of the robot have been processed and connected to the substrate through the "island chain"; c. Cutting material 37 along the dotted line can release all the parts required to form the four-degree-of-freedom micro-surgical robot from the substrate, and material 38 is the remaining substrate plate after the parts 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. At this point, the production of all parts of the four-degree-of-freedom micro-surgical robot is completed.

The assembly process is as follows: d. Part 39 corresponds to FIG2 and is the moving platform mechanism of the four-degree-of-freedom micro-surgical robot. Part 40 corresponds to FIG5 and is the upper branch of the branch mechanism A. Part 41 corresponds to FIG3 and is the lower branch of the branch mechanism A. Part 42 corresponds to FIG6 and is the upper branch of the branch mechanism D. Part 43 corresponds to FIG4 (the letter C is changed to D) and is the lower branch of the branch mechanism D. As shown in sub-figure d, insert the male plugs of parts 40 and 42 into the female plug of part 39, insert the male plug of part 41 into the female plug of part 40, and insert the male plug of part 43 into the female plug of part 42. e. After completing the plug-in of branch mechanisms A, B, C, and D according to the method shown in sub-figure d, fix the plug-in position with glue and fully solidify it to obtain the robot body. At this point, the four-degree-of-freedom micro-surgical robot is 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.

The power required to control the micro-surgical robot is transmitted through the lower branches of the four branched chain mechanisms (the sixth link 6 in the branched chain mechanisms A and C and the eighth link 8 in the branched chain mechanisms B and D). According to the parameter requirements of the theoretical model, when the input link rotation axis position is fixed, the four input links are controlled by the rotation drive mechanism to achieve the four-degree-of-freedom control of the moving platform (fifth link 5) in the working space of the micro-surgical robot.

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, and 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. The lower branch of each branch mechanism is equipped with a rotation drive mechanism fixed on the base, which is used to drive the branch mechanism to rotate around the corresponding rotation center axis.

The above-mentioned angle control function can be realized by various commonly used rotation drive mechanisms according to the working conditions and precision requirements, such as: piezoelectric ceramic drive, motor drive, wire drive, electromagnetic drive, friction drive, shape memory alloy drive, flexible material deformation drive, etc. This embodiment uses mechanical transmission and motor drive as demonstration. Each rotation drive mechanism includes a drive motor and a transmission plate. The transmission plate is assembled on the drive shaft of the drive motor and the plate surface is perpendicular to the drive shaft. A boss structure is provided on the transmission plate to provide a mounting plane for the protruding section of the sixth connecting rod. The specific assembly form of this rotation drive mechanism is shown below.

FIG13 shows a micro-surgical robot and its drive transmission system. Sub-figure a is an assembly diagram of the motor and the transmission plate, in which part 45 is a micro-servo motor, part 46 is a transmission plate, and part 47 is bolt No. 1. There are three through holes on the transmission plate for fixing the motor with bolt No. 1, and two bolt holes for connecting and fixing the micro-surgical robot. The function of the transmission plate is to connect the micro-servo motor and the micro-surgical robot, and to make the rotation axis of the robot input connecting rod coincide with the rotation axis of the motor and meet the robot construction requirements of the theoretical model.

Sub-figure b is the assembly diagram of the micro-surgical robot and the transmission plate, in which part 48 is bolt No. 2 and part 49 is the inverted micro-surgical robot body. As shown in the figure, bolt No. 2 connects the robot to the transmission plate through two through holes on the input connecting rod. Sub-figure c is the assembly diagram of the motor and the base, in which part 50 is bolt No. 3 and part 51 is the base. The base has four inclined planes for fixing the motor according to the requirements of the theoretical model, and each inclined plane has four through holes. Bolt No. 3 fixes the motor and the base together through these through holes, and finally obtains sub-figure d. Sub-figure d shows the result schematic diagram of the above assembly process. At this point, the four-degree-of-freedom micro-surgical robot system is completed. The metal base fixes the fixed platform of the robot through the motor and the transmission plate. At this time, the actual mechanism parameters of the robot are consistent with the theoretical model parameters. The precise control of the robot's moving platform can be achieved by controlling the angle of the small servo motor, so that the actuator of the moving platform can achieve the target task.

FIG14 is a schematic diagram showing the degrees of freedom of motion of the micro robot moving platform. In the figure, the origin O of the earth coordinate system coincides with the RCM point of the robot, the x-axis is parallel to the distribution direction of the branch mechanism A, the y-axis is parallel to the distribution direction of the branch mechanism D, and the O’ point is the geometric center of the robot moving platform. As shown in sub-figures a to d, the rotational freedom of the micro surgical robot moving platform around the x-axis; the rotational freedom around the y-axis; the rotational freedom around the z-axis; and the translational freedom along the z-axis are shown. It can be seen that the straight line perpendicular to the moving platform through point O’ always passes through point O, so point O is an RCM point of the micro robot.

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., 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, three implementation examples of blades, micro cameras, and injection needles are listed in the present invention. In sub-figure a, a micro-surgical robot model with a blade installed for cutting tasks is listed; in sub-figure b, a micro-surgical robot model with a micro camera installed for performing surgical environment imaging tasks is listed; in sub-figure c, a micro-surgical robot model with an injection needle installed for puncture tasks is listed.

The above-mentioned Figures 1 to 14 show the theoretical model, specific form and processing method of a four-degree-of-freedom micro-surgical robot with four branched chain mechanisms, but this is only a preferred implementation method, and the present invention is not limited to this. The number of branched chain mechanisms in the present invention can be reasonably adjusted according to actual needs, and there can be two or more branched chain mechanisms. At this time, the form of the moving platform mechanism also needs to be adaptively adjusted according to the number of branched chain mechanisms. The basic requirement for the moving platform mechanism is that the moving platform mechanism needs to include a central connecting rod with a polygonal plane and a branched chain connecting rod connected to the side of the central connecting rod by a hinge, wherein the central connecting rod serves as a moving platform for installing surgical equipment, and the number of branched chain connecting rods and the number of sides of the polygon are not less than the number of branched chain mechanisms. Further, since the number of branched chain mechanisms may not match the number of rotary drive mechanisms, in the above-mentioned four-degree-of-freedom micro-surgical robot control system of the present invention, the order of installing all rotary drive mechanisms on each branched chain mechanism is as follows: first, a rotary drive mechanism fixed to a base is assembled on the lower branch of each branched chain mechanism, which is used to drive the branched chain mechanism to rotate around the corresponding said rotation center axis. The number of rotary drive mechanisms should generally be equal to the number of branch chain mechanisms, and of course it can also be greater than the number of branch chain mechanisms, but the redundant rotary drive mechanisms may be redundant. However, since the number of branch chain mechanisms in the robot is at least 2, although the above embodiment shows the case where the number of branch chain mechanisms is 4, it is also possible that there are 2, 3, or even 5 or more cases, that is, the number of rotary drive mechanisms and the number of branch chain mechanisms are not necessarily matched. If the number of branch chain mechanisms and rotary drive mechanisms is exactly four, then as seen in the above embodiment, the rotary drive mechanism and the branch chain mechanism form a driving relationship in a one-to-one correspondence, and each branch chain mechanism is equipped with a rotary drive mechanism fixed on the base on the lower branch chain, and the output shaft axis of this rotary drive mechanism coincides with the rotation center axis on the lower branch chain. However, if the number of rotary drive mechanisms is greater than the number of branch chain mechanisms, in addition to the rotary drive mechanism fixed on the base on the lower branch chain of each branch chain mechanism, the remaining rotary drive mechanisms need to be installed on the upper branches of different branch chain mechanisms to drive the branch chain mechanism to rotate around the seventh hinge in this branch chain mechanism. The rotary drive mechanism installed on the upper branch chain of the branch chain mechanism can move in space along with the overall rotation drive mechanism without the need for installation through a base.

As shown in Figure 16, the left figure shows the main body of a four-degree-of-freedom micro-surgical robot with only two branch mechanisms, and the right figure shows a four-degree-of-freedom micro-surgical robot control system formed by assembling the robot on a base. In this four-degree-of-freedom micro-surgical robot control system, there are four rotary drive motors, two of which are fixed on the base and are used to drive the two branch mechanisms to rotate around their respective rotation center axes, while the other two rotary drive motors marked as M in the figure are installed on the upper branches of the two branch mechanisms, and are used to drive the branch mechanisms to rotate around the seventh hinge in the branch mechanism.

As shown in FIG17 , the left figure shows the main body of a four-degree-of-freedom micro-surgical robot with only three branching mechanisms, and the right figure shows a four-degree-of-freedom micro-surgical robot control system formed by assembling the robot on a base. In this four-degree-of-freedom micro-surgical robot control system, there are four rotary drive motors, three of which are fixed on the base and are used to drive the three branching mechanisms to rotate around their respective rotation center axes, and the other rotary drive motor marked as M in the figure is installed on the upper branch of any one of the branching mechanisms, and is used to drive the branching mechanism to rotate around the seventh hinge in the branching mechanism.

As shown in Figure 18, the left figure shows the main body of a four-degree-of-freedom micro-surgical robot with six branch chain mechanisms, and the right figure shows a four-degree-of-freedom micro-surgical robot control system formed after the robot is assembled on the base. In this four-degree-of-freedom micro-surgical robot control system, there are six rotary drive motors fixed on the base, which are used to drive the six branch chain mechanisms to rotate around their respective rotation center axes. Of course, in this approach, it is also possible to continue to increase the number of rotary drive motors, and the additional motors can be installed on the upper branch chain of any branch chain mechanism to drive the branch chain mechanism to rotate around the seventh hinge in the branch chain mechanism, but these motors are redundant and can be cancelled.

In addition, for each branch chain 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 chain and the lower branch chain can also be adjusted or simplified based on the aforementioned preferred embodiment.

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 exist 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 rotation through the hinge. However, it should be specially noted that the two connecting rods are connected by a fixed connection here, which can refer to the two being fixedly connected by splicing methods such as male and female heads, or they can be directly integrated during the processing, that is, there is no physical seam at the splicing position, and the two connecting rods are actually integrated.

In addition, as another form of deformation, the side edge of the protruding section of the sixth connecting rod does not necessarily have to be colinear with the side edge of the second straight bar segment. When the two are not colinear, the straight line where the side edge of the second straight bar segment away from the circular ring segment is located is used as the rotation center axis 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 connecting rod 6 and a seventh connecting rod 7, the sixth connecting rod 6 includes a main section and a protruding section, the main section is continuously composed of a first straight bar segment, a circular ring segment and a second straight bar segment of equal width, the seventh connecting rod 7 is fixedly connected to the outer end of the first straight bar segment or is rotatably connected through 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 an external driving mechanism; and the straight line where the side edge of the second straight bar segment away from the circular ring segment is located is used as the rotation center axis when the lower branch chain is driven. The most basic requirement for each upper branch chain is to meet the following requirements: the upper branch chain is composed 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 is rotatably connected through the sixth hinge, the other end of the eleventh link 11 is rotatably connected to one end of the twelfth link 12 through the seventh hinge, the other end of the twelfth link 12 is rotatably connected to the thirteenth link 13 through the eighth hinge, and the thirteenth link 13 is fixedly spliced with the corresponding branch link on the moving platform mechanism through male and female heads. The lower branch chain and the upper branch chain still need to be fixedly spliced through a set of male and female heads respectively provided on the seventh link 7 and the tenth link 10.

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:

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 chain, 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 chain, 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.

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

The first basic constraint is that at least one of the fifth hinge and the sixth hinge of each branch mechanism exists. If both exist, the hinge axes of the two hinges must coincide.

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

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

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;

The fifth basic constraint is that the first center and the second center of all branch chain mechanisms coincide with the same point.

The above five basic constraints need to be satisfied for any micro-surgical robot with any number of branches, but for different actual micro-surgical robots, whether other constraints need to be satisfied 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 4×6=24 mechanism parameters in total. In order to ensure that the mechanism has a larger working space and better transmission performance, these mechanism parameters can further satisfy the following four optimization constraints:

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

The second optimization constraint is that the parameters of each set of branch mechanisms facing each other are the same, that is, the second posture angle α2, the third posture angle α3, the first hinge spacing L1, and the second hinge spacing L2 of the first branch mechanism and the third branch mechanism are the same, and the second posture angle α2, the third posture angle α3, the first hinge spacing L1, and the second hinge spacing L2 of the second branch mechanism and the fourth branch mechanism are also the same;

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

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°.

In addition, it should be noted that the first posture angle α1 of each branch mechanism is formed only after the robot and the drive mechanism are installed, and cannot be constrained before they are assembled. However, when the robot and the drive mechanism are assembled, the first posture angle α1 also needs to be added with the above-mentioned second constraint, that is, the first posture angle α1 of the first branch mechanism is the same as that of the third branch mechanism, and the first posture angle α1 of the second branch mechanism and the fourth branch mechanism also needs to be kept the same. For the robot with four branch mechanisms in the above embodiment, it is best to keep the first posture angles α1 of the four branch mechanisms exactly the same.

The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims (13)

1. A four-degree-of-freedom miniature surgical robot with a distal movement center is characterized by comprising a movable platform mechanism and at least 2 branched chain mechanisms, wherein the movable platform mechanism is formed by processing a composite lamellar material plane;

The movable platform mechanism comprises a central connecting rod with a polygonal plane and branched chain connecting rods connected to the side edges of the central connecting rod through hinges, the central connecting rod is used as a movable platform for installing surgical equipment, and the number of the branched chain connecting rods and the number of the sides of the polygon are not less than the number of the branched chain mechanisms;

Each branched chain mechanism is identical in form and is formed by splicing an upper branched chain and a lower branched chain;

The lower branched chain consists of an integrated sixth connecting rod (6) and a seventh connecting rod (7), the sixth connecting rod (6) comprises a main body section and a protruding section, the main body section consists of a first straight section, a circular ring section and a second straight section with equal width in succession, the seventh connecting rod (7) is fixedly connected with the outer end part of the first straight section or is rotationally connected with the outer end part of the first straight section through a fifth hinge, and 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 second straight segment is far away from the side edge of the circular ring segment is used as a rotation central shaft when the lower branched chain is driven;

the upper branched chain consists of an integral tenth connecting rod (10), an eleventh connecting rod (11), a twelfth connecting rod (12) and a thirteenth connecting rod (13); the tenth connecting rod (10) is fixedly connected with one end of the eleventh connecting rod (11) or rotationally connected through a sixth hinge, the other end of the eleventh connecting rod (11) is rotationally connected with one end of the twelfth connecting rod (12) through a seventh hinge, the other end of the twelfth connecting rod (12) is rotationally connected with the thirteenth connecting rod (13) through an eighth hinge, and the thirteenth connecting rod (13) and a branched chain connecting rod corresponding to the movable platform mechanism are fixedly spliced through a male head and a female head;

The lower branched chain and the upper branched chain are fixedly spliced through a group of male and female heads respectively arranged on a seventh connecting rod (7) and a tenth connecting rod (10);

all branching mechanisms assembled on the central link satisfy the following five constraints:

the first constraint is: at least one fifth hinge and at least one sixth hinge of each branched mechanism exist, and if the fifth hinge and the sixth hinge exist at the same time, hinge axes of the fifth hinge and the sixth hinge need to be overlapped;

The second constraint is: the axes of the seventh hinge and the eighth hinge of each branched mechanism are mutually perpendicular;

The third constraint is: the second attitude angle and the third attitude angle of each branched chain mechanism are smaller than 180 degrees;

the fourth constraint is: the eighth hinge in each branched chain mechanism is parallel to the hinge connected with the current branched chain mechanism on the movable platform;

The fifth constraint is: the first circle centers and the second circle centers in all the branched chain mechanisms are overlapped on the same point;

In each branched chain mechanism, the fifth hinge or the sixth hinge is used as a designated hinge, the intersection point of the designated hinge and the rotation central shaft is used as a first circle center, the intersection point of the designated hinge and the seventh hinge is used as a second circle center, the included angle between the designated hinge and the rotation central shaft is used as a second attitude angle, and the included angle between the designated hinge and the seventh hinge is used as a third attitude angle.

2. The four-degree-of-freedom miniature surgical robot with a distal movement center according to claim 1, wherein in the movable platform mechanism, a central connecting rod is a rectangular fifth connecting rod (5), four branched chain connecting rods connected on the fifth connecting rod (5) are respectively a first connecting rod (1), a second connecting rod (2), a third connecting rod (3) and a fourth connecting rod (4), one ends of the first connecting rod (1), the second connecting rod (2), the third connecting rod (3) and the fourth connecting rod (4) are respectively connected with the fifth connecting rod (5) in a rotating way through a first hinge, a second hinge, a third hinge and a fourth hinge, and the other ends of the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod are respectively fixedly connected with the first branched chain mechanism, the second branched chain mechanism and the fourth branched chain mechanism through a male-female joint; 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;

The combined mechanism of the first connecting rod (1) and the first branched mechanism and the combined mechanism of the third connecting rod (3) and the third branched mechanism are symmetrically distributed on two sides of the movable platform, and the combined mechanism of the second connecting rod (2) and the second branched mechanism and the combined mechanism of the fourth connecting rod (4) and the fourth branched mechanism are symmetrically distributed on two sides of the movable platform.

3. The four-degree-of-freedom microsurgical robot with distal center of motion of claim 2, wherein the robot body mounted on four rotary drive mechanisms satisfies four constraints:

The first constraint is: equivalent radiuses of the lower branched chain and the upper branched chain of the four branched chain mechanisms are the same;

The second constraint is: the second attitude angle, the third attitude angle, the first hinge spacing and the second hinge spacing of the first branched chain mechanism and the third branched 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 branched chain mechanism and the fourth branched chain mechanism are the same;

The third constraint is: the first hinge spacing and the second hinge spacing of each of the four branched chain mechanisms are 0.2-2 times of the equivalent radius;

The fourth constraint is: the second attitude angle and the third attitude angle of each of the four branched chain mechanisms are smaller than 90 degrees;

In each branched chain mechanism, the distance from the first circle center to the farthest end of the appointed hinge or the distance from the first circle center to the farthest end of the second straight strip section far away from the side edge of the circular ring section is used as the equivalent radius of the lower branched chain, the distance from the second circle center to the eighth hinge is used as the equivalent radius of the upper branched chain, the included angle between the rotation center shaft and the horizontal plane is used as a first attitude angle, the distance from the eighth hinge to the hinge connected with the current branched chain mechanism on the movable platform is used as a first hinge distance, and the half distance from the hinge connected with the current branched chain mechanism on the movable platform to the symmetrical hinge is used as a second hinge distance.

4. The four-degree-of-freedom microsurgical robot with a distal movement center according to claim 1, wherein all the links of the four-degree-of-freedom microsurgical robot are made of a composite layered material, the middle layer of the composite layered material is a flexible planar material layer, the two sides of the middle layer are rigid planar material layers, the flexible planar material layer and the rigid planar material layer are adhered and fixed by an adhesive material layer, the flexible planar material layer is kept continuous by the adjacent two links at the hinge position, the rigid planar material layer is broken, and the edges of the rigid planar material layers at the two sides of the broken position are provided with rectangular grooves at intervals and are mutually jogged by the edges of the saw tooth form formed by the rectangular grooves, so that the flexible planar material layer can freely rotate around the hinge under the coupling action of the flexible planar material layer.

5. The four-degree-of-freedom microsurgical robot with a distal center of motion of claim 4, wherein the flexible planar material layer is a soft high molecular polymer film, a soft gel layer, a soft woven cloth, a soft metal foil; the hard flat material layer is a hard metal plate, a hard plastic plate, a hard glass plate, a hard resin plate, a hard wood plate and a hard composite material plate.

6. The four-degree-of-freedom microsurgical robot with a distal movement center according to claim 1, wherein the male and female heads connecting the two links are separately provided on the two links, the male head of one link is assembled to the female head of the other link, and the two links are coupled together by glue fixing.

7. A four-degree-of-freedom microsurgical robot control system with a distal center of motion, comprising the four-degree-of-freedom microsurgical robot of any one of claims 1-6 and at least four independent rotational drive mechanisms;

Wherein the lower branched chain of each branched chain mechanism is provided with a rotary driving mechanism fixed on a base (51) and used for driving the branched chain mechanism to rotate around the corresponding rotary central shaft; if the number of the rotary driving mechanisms is greater than that of the branched chain mechanisms, the rest rotary driving mechanisms are arranged on the upper branched chains of different branched chain mechanisms and used for driving the branched chain mechanisms to rotate around the corresponding seventh hinges;

And each branched chain mechanism takes the included angle between the rotation central shaft and the horizontal plane as a first attitude angle in the assembled state with the rotation driving mechanism, and the first attitude angle of each branched chain mechanism is smaller than 90 degrees.

8. The four-degree-of-freedom microsurgical robotic control system with a distal center of motion of claim 7, wherein the number of said branching mechanisms and said rotary drive mechanisms is four, the rotary drive mechanisms and said branching mechanisms being in one-to-one correspondence in driving relationship.

9. The four-degree-of-freedom microsurgical robotic control system having a distal center of motion of claim 8, wherein the first pose angles of the four branching mechanisms are the same.

10. The four-degree-of-freedom microsurgical robotic control system with remote center of motion of claim 7, wherein each of said rotary drive mechanisms comprises a drive motor (45) and a drive plate (46), the drive plates (46) being mounted on the drive shafts of the drive motors (45) with the plate faces perpendicular to the drive shafts, the drive plates (46) providing mounting planes for the protruding sections of the sixth link (6) by means of a boss structure.

11. The four-degree-of-freedom microsurgical robotic control system with remote center of motion of claim 10, wherein the drive motor (45) is a miniature servo motor.

12. The four-degree-of-freedom microsurgical robotic control system with a distal center of motion of claim 7, wherein the central linkage has a mounting hole in its center through which surgical instruments are mounted.

13. The four-degree-of-freedom microsurgical robotic control system with a distal center of motion of claim 12, wherein the surgical instrument comprises one or more of a blade, a miniature camera, an injection needle, a lens, or a suction cup.