A parallel robot platform based on flexible cable and continuum composite drive

Abstract

The present invention relates to a parallel robot platform based on a composite drive of flexible cables and continuums, comprising a support frame and a working platform suspended above the support frame, the working platform being used to connect an end effector; the working platform is evenly provided with three groups of flexible continuum robotic arms of identical structure along its circumference, the head ends of the three groups of flexible continuum robotic arms being rotatably connected to the working platform via ball-joint universal joint assemblies, and the ends of the three groups of flexible continuum robotic arms being respectively connected to a robotic arm drive mechanism. As can be seen from the above technical solution, the present invention not only improves the interactive safety of the robot, but also enhances the accuracy and stability of the end effector while retaining the flexibility of the continuum robot.

Description

Technical Field

[0001] The present invention relates to the field of robots, and in particular to a parallel robot platform based on flexible cable and continuum composite drive. Background Art

[0002] A parallel robot is a mechanical device based on a closed-loop motion chain structure, and is widely used in precision assembly, high-speed sorting, national defense science and technology and other fields. In order to achieve the complex spatial motion of the end effector, the robot is often required to be able to achieve six-degree-of-freedom posture changes in space. Common six-degree-of-freedom parallel robots mostly adopt the Stewart configuration. The dynamic platform and the static platform are coordinated by six retractable connecting rods. The dynamic platform can achieve different postures by controlling the six connecting rods for extension and retraction. It has the characteristics of high rigidity, high precision and fast response of the end effector. It can be used for motion simulation platforms, precise positioning, etc. This type of six-degree-of-freedom parallel robot requires six branches, and each branch is a rigid structure. In occasions such as medical surgery, it needs to be combined with a high-precision force feedback system to ensure its interactive safety.

[0003] Continuum robots are a new type of biomimetic robot inspired by the flexible structures of animals found in nature, such as elephant trunks and octopus tentacles. Made of flexible, elastic materials, they are highly flexible, compliant, and jointless. They can continuously change shape under the influence of actuators, enabling a variety of movements such as bending and rotation. They have demonstrated unique advantages in fields such as search and rescue and industrial repair. However, traditional multi-degree-of-freedom continuum robots are typically composed of multiple continuum segments connected in series, with complex drive mechanisms. During operation, due to factors such as friction and tube gaps, errors accumulate during the transmission of each continuum segment, resulting in reduced precision of the end effector.

[0004] While some current robots combine the advantages of both, there are still areas for improvement. Patent publication number CN108422413A discloses a flexible continuous parallel robot with variable stiffness. While this invention boasts flexible movement, controllable stiffness, and strong adaptability, its drive components are susceptible to damage under continuous torsion and deformation, shortening its service life. Patent publication number CN114800454A discloses a continuum robot based on a compliant Stewart parallel mechanism. While this invention boasts high flexibility and strong torsion resistance, its kinematic model is complex and its manufacturing is difficult. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned drawbacks and provide a parallel robot platform based on a composite drive of flexible cables and continuum.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: comprising a support frame and a work platform suspended above the support frame, the work platform being used to connect to an end effector; the work platform being evenly provided with three groups of flexible continuum robotic arms of identical structure along its circumference, the head ends of the three groups of flexible continuum robotic arms being rotatably connected to the work platform via ball-joint universal joint assemblies, and the ends of the three groups of flexible continuum robotic arms being respectively connected to a robotic arm drive mechanism;

[0007] The robotic arm drive mechanism includes a square frame body, a screw-nut mechanism and a flexible cable drive mechanism arranged in the frame body. One end of the frame body is fixedly connected to the stepper motor mounting plate, and the other end of the frame body is provided with a continuum mounting plate movably connected to the frame body. The continuum mounting plate is fixed to the end of the flexible continuum robotic arm.

[0008] The screw-nut mechanism includes a screw, one end of which is connected to a first stepper motor fixed to a stepper motor mounting plate, and the other end of which passes through the stepper motor mounting plate and the continuum mounting plate, and a first screw nut that cooperates with the screw is fixed to the continuum mounting plate. The first stepper motor drives the screw to rotate, thereby causing the continuum mounting plate to displace axially along the screw to achieve forward and backward displacement of the flexible continuum robotic arm.

[0009] The flexible cable drive mechanism includes a servo electric cylinder and a flexible cable, one end of the flexible cable is fixed to the push rod end of the servo electric cylinder, and the other end of the flexible cable passes through the flexible continuum robotic arm and is fixed to the head end of the flexible continuum robotic arm; the flexible cables and servo electric cylinders are respectively arranged in three groups, and the three groups of flexible cables respectively cause the flexible continuum robotic arm to deform under the driving cooperation of the three groups of servo electric cylinders to realize the pitch and deflection adjustment of the flexible continuum robotic arm.

[0010] The frame body is fixed on the driving mechanism support frame, one end of the driving mechanism support frame is hinged to the top of the support frame through a first hinge, and the other end of the driving mechanism support frame is connected to the angle adjustment mechanism;

[0011] The angle adjustment mechanism includes a screw nut slider mechanism and a connecting rod. The screw nut slider mechanism is arranged on the layer plate of the support frame. The screw nut slider mechanism includes a ball screw, a screw nut seat matching the ball screw, a nut slide fixed on the screw nut seat, and a second stepper motor that drives the ball screw to rotate; one end of the connecting rod is hinged to the nut slide through a second hinge, and the other end of the connecting rod is hinged to the drive mechanism support frame through a third hinge. The connecting rod, the drive mechanism support frame, the first hinge and the nut slide form a crank slider mechanism. When the second stepper motor drives the nut slide along the axial displacement of the ball screw through the ball screw, the connecting rod drives the drive mechanism support frame to rotate around the hinge axis of the first hinge to realize the adjustment of the pitch angle of the robotic arm drive mechanism.

[0012] The screw nut slider mechanism also includes slide rails symmetrically arranged on both sides of the ball screw, sliders slidingly matched with the slide rails, and a connecting bracket fixed on the slider, wherein the connecting bracket is fixed to the nut slider.

[0013] The supporting frame is a triangular structure as a whole, including an upper triangular frame, a lower triangular frame and a column connecting the two. A layer plate parallel to the upper triangular frame and the lower triangular frame is provided between the upper triangular frame and the lower triangular frame. The layer plate is fixed to the column by installing a tripod. The bottom of the lower triangular frame is also covered with a base plate, and the bottom of the lower triangular frame is also provided with an adjustable foot.

[0014] The flexible continuum robotic arm is an integrally constructed tubular annular continuum, which is connected by multiple identical annular bodies. Each annular body is annularly cut with three equal arcs. One end of the flexible continuum robotic arm is connected to the ball head universal joint assembly through a first flange, and the other end of the flexible continuum robotic arm is fixed to the continuum mounting plate of the robotic arm drive mechanism through a second flange; the flexible continuum robotic arm is evenly arranged with three groups of flexible cable holes along its circumference, and the three groups of flexible cable holes are all set through the flexible continuum robotic arm.

[0015] The ball joint assembly includes a ball rod and a ball seat that cooperate with each other, the ball seat is fixed to the working platform, and the ball rod is connected to the flexible continuum robot arm through a connecting piece;

[0016] The connecting part includes a rod-shaped connecting head and a third flange. A first threaded hole is provided at one end of the connecting head, and the first threaded hole is cooperated with the threaded section on the ball head rod. A second threaded hole is provided at the other end of the connecting head, and the second threaded hole is fixed to the third flange by a bolt. The third flange is fixed to the first flange at the end of the flexible continuum robotic arm.

[0017] The working platform is a triangular block structure as a whole, and its three corners respectively form U-shaped ear seats for fixing the ball head seat. Connecting shafts are symmetrically arranged on the outer wall of the ball head seat, and the two ends of the connecting shaft are respectively connected to the ball head seat and the U-shaped ear seat through miniature bearings.

[0018] A servo electric cylinder mounting plate and a servo electric cylinder push rod mounting plate are respectively provided between the stepper motor mounting plate and the continuum mounting plate, wherein: the continuum mounting plate and the servo electric cylinder push rod mounting plate are fixedly connected by a first connecting plate, and the servo electric cylinder push rod mounting plate and the servo electric cylinder mounting plate are fixedly connected by a second connecting plate, and the servo electric cylinder push rod mounting plate and the servo electric cylinder mounting plate are respectively provided with a second screw nut and a third screw nut that match the screw rod, and the continuum mounting plate, the servo electric cylinder push rod mounting plate and the servo electric cylinder mounting plate form a component that moves as a whole on the screw rod.

[0019] The cylinder body end of the servo electric cylinder is fixed on the servo electric cylinder mounting plate, and the push rod end of the servo electric cylinder passes through the servo electric cylinder push rod mounting plate and is fixed to the flexible cable through a flexible cable connector; through holes are respectively provided at both ends of the flexible cable connector, wherein the through hole at one end is used to fix the flexible cable, and a screw joint is installed at the through hole at the other end, and the screw joint is threadedly connected to the push rod of the servo electric cylinder.

[0020] The frame body includes guide columns arranged perpendicular to the four corners of the stepper motor mounting plate and a cross bar connecting two adjacent guide columns. The four corners of the servo electric cylinder mounting plate, the servo electric cylinder push rod mounting plate and the continuum mounting plate are respectively provided with square notches for avoiding the guide columns; the first stepper motor is arranged in two groups, and the two groups of first stepper motors are fixed on the stepper motor mounting plate in a diagonal direction.

[0021] The beneficial effects of the present invention are:

[0022] 1. The flexible continuum robot arm of this invention possesses four degrees of freedom. In addition to the inherent pitch and yaw degrees of freedom within the robot arm, two redundant degrees of freedom are introduced through a screw-nut mechanism and an angle adjustment mechanism. This provides greater flexibility than a traditional two-DOF continuum. Furthermore, this structure enriches the motion poses of the end effector, enabling it to perform more complex spatial motion tasks, significantly improving the robot's adaptability and performance in a variety of application scenarios.

[0023] 2. The present invention realizes the six-degree-of-freedom motion of the end effector in space by adopting a parallel mechanism, which is a flexible motion chain driven by three flexible cables and a continuum composite drive in parallel, thereby improving the passive compliance of the robot and making the robot have better interactive safety in medical surgery and other occasions.

[0024] 3. The present invention adopts a composite drive system that combines a stepper motor, a servo electric cylinder and a flexible cable, which enables the robot to have excellent precision and flexibility when performing tasks.

[0025] 4. The present invention replaces the motion branches of the parallel robot with a two-degree-of-freedom continuum robot, so that each motion chain in the parallel structure can be designed to be shorter and simpler, thereby improving the kinematic performance in terms of accuracy and dynamic performance, reducing the accumulation of errors, and improving the stability and reliability of the robot in precision operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the three-dimensional structure of the present invention Figure 1 ;

[0027] Figure 2 This is a schematic diagram of the three-dimensional structure of the present invention Figure 2 ;

[0028] Figure 3 It is a schematic diagram of the working state of the present invention;

[0029] Figure 4 yes Figure 3 A magnified view of part A;

[0030] Figure 5 It is a structural schematic diagram of the support frame of the present invention;

[0031] Figure 6 It is a structural schematic diagram of the working platform of the present invention;

[0032] Figure 7 It is a structural schematic diagram of the flexible continuum mechanical arm and the ball head rod of the present invention;

[0033] Figure 8 yes Figure 7 Schematic diagram of the decomposition structure;

[0034] Figure 9 Schematic diagram of the connection between the flexible continuum manipulator and the flexible cable of the present invention;

[0035] Figure 10 It is a schematic diagram of the overall structure of the robot arm drive mechanism of the present invention;

[0036] Figure 11 This is a schematic diagram of the internal structure of the robot arm drive mechanism of the present invention. Figure 1 ;

[0037] Figure 12 This is a schematic diagram of the internal structure of the robot arm drive mechanism of the present invention. Figure 2 ;

[0038] Figure 13 Schematic diagram of the exploded structure of the robot arm drive mechanism of the present invention;

[0039] Figure 14 This is the usage state of the screw nut mechanism of the present invention Figure 1 ;

[0040] Figure 15 This is the usage state of the screw nut mechanism of the present invention Figure 2 ;

[0041] Figure 16 It is a structural schematic diagram of a single-group angle adjustment mechanism of the present invention.

[0042] The symbols in the above drawings are: support frame 1, upper triangular frame 11, lower triangular frame 12, column 13, layer 14, mounting bracket 15, bottom plate 16, adjustable foot 17, first hinge 18, working platform 2, U-shaped ear seat 21, flexible continuum robot arm 3, first flange 31, second flange 32, flexible cable hole 33, ball head universal joint assembly 4, ball head rod 41, ball head seat 42, connecting shaft 421, miniature bearing 422, connecting piece 43, connecting head 431, third flange 432, robot arm drive mechanism 5, frame body 501, guide column 5011, cross bar 5012, stepper motor mounting plate 502, servo Electric cylinder mounting plate 503, servo electric cylinder push rod mounting plate 504, continuum mounting plate 505, first connecting plate 506, second connecting plate 507, screw 511, first stepper motor 512, first screw nut 513, second screw nut 514, third screw nut 515, servo electric cylinder 521, flexible cable 522, flexible cable connector 523, screw joint 524, drive mechanism support frame 6, angle adjustment mechanism 7, connecting rod 71, second hinge 711, third hinge 712, ball screw 72, screw nut seat 73, nut slide plate 74, second stepper motor 75, slide rail 76, slider 77, connecting bracket 78. DETAILED DESCRIPTION

[0043] The present invention will be further described below with reference to the accompanying drawings:

[0044] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 The parallel robot platform shown is based on a composite drive of flexible cables and continuums, and includes a support frame 1 and a working platform 2 suspended above the support frame 1, the working platform 2 being used to connect the end effector; the working platform 2 is evenly provided with three groups of flexible continuum robotic arms 3 with the same structure along its circumference, the head ends of the three groups of flexible continuum robotic arms 3 are respectively connected to the working platform 2 through ball head universal joint assemblies 4, and the ends of the three groups of flexible continuum robotic arms 3 are respectively connected to the robotic arm drive mechanism 5.

[0045] Further, such as Figure 5As shown, the support frame 1 serves as the supporting part of the entire parallel robot platform and bears the entire weight of the parallel robot platform. In this embodiment, the support frame 1 is arranged in a triangular structure. Specifically, the support frame 1 is a triangular structure as a whole, including an upper triangular frame 11, a lower triangular frame 12 and a column 13 connecting the two. The support frame 1 is made of profiles. A layer 14 parallel to the upper triangular frame 11 and the lower triangular frame 12 is also provided between the upper triangular frame 11 and the lower triangular frame 12. The layer 14 is fixed to the column 13 by installing a tripod 15. The bottom of the lower triangular frame 12 is also covered with a base plate 16. The base plate 16 is made of sheet metal and is convenient for storing drivers, power supplies and other accessories. The bottom of the lower triangular frame 12 is also provided with an adjustable foot 17. The adjustable foot 17 can be adjusted according to the ground conditions to ensure the levelness of the entire parallel robot platform and flexibly adapt to different working environments.

[0046] Further, such as Figure 6 As shown, the work platform 2 has an overall triangular block structure, with its three corners forming U-shaped ears 21 for securing the ball head seat 42. To prevent collision between the work platform 2 and the ball head seat 42 during movement, the distance between the two ear plates of the U-shaped ears 21 should be slightly larger than the outer diameter of the ball head seat 42, and the bottom surface of the U-shaped ears 21 is designed to be curved. A through hole is opened in the center of the work platform 2 to reduce the weight of the work platform 2 and achieve a lightweight design. In actual work, end effectors with different functions such as grasping, handling, and assembly can be connected to the work platform 2 according to different tasks and needs to complete various tasks.

[0047] Further, such as Figure 7 As shown, the flexible continuum manipulator 3 is a tubular annular continuum of integral construction, formed by connecting multiple identical annular segments. Each annular segment is annularly cut with three equal arcs, enabling the continuum to simultaneously possess excellent bending properties and axial tensile stiffness. Preferably, the flexible continuum manipulator 3 is made of an elastic metal material, such as nickel-titanium alloy, and the manufacturing process is laser cutting or wire cutting. One end of the flexible continuum manipulator 3 is connected to the ball joint assembly 4 via a first flange 31, and the other end of the flexible continuum manipulator 3 is fixed to the continuum mounting plate 505 of the manipulator drive mechanism 5 via a second flange 32. In this embodiment, the first flange 31 is circular, and the second flange 32 is triangular, with rounded corners, which reduces the effects of stress concentration and effectively prevents breakage of the manipulator. The flexible continuum manipulator 3 is evenly arranged with three sets of flexible cable holes 33 along its circumference, and all three sets of flexible cable holes 33 are arranged throughout the flexible continuum manipulator 3.

[0048] When working, Figure 3 、 Figure 4As shown, three groups of flexible continuum robotic arms 3 are driven separately by three groups of flexible cables 522, and all produce a certain angle of deformation. The ball head rod 41 corresponding to each group of robotic arm driving mechanism 5 transmits the motion to the corresponding ball head seat 42. The three motion chains cooperate with each other to jointly drive the working platform 2, so that the end effector fixed on the working platform 2 can complete complex spatial motion.

[0049] Further, such as Figure 6 、 Figure 8 、 Figure 9 As shown, the ball head universal joint assembly 4 includes a ball head rod 41 and a ball head seat 42 that cooperate with each other, wherein: the ball head seat 42 is fixed to the working platform 2, and the ball head rod 41 is connected to the flexible continuum robot arm 3 through a connecting piece 43.

[0050] Specifically, the connector 43 includes a rod-shaped connector 431 and a third flange 432. A first threaded hole is provided at one end of the connector 431, and the first threaded hole is mated with a threaded section on the ball rod 41. A second threaded hole is provided at the other end of the connector 431, and the second threaded hole is fixed to the third flange 432 via bolts. The third flange 432 is fixed to the first flange 31 at the end of the flexible continuum robotic arm 3 via bolts. A bolt hole is provided at the center of the third flange 432 for connecting the third flange 432 to the connector 431. The third flange 432 also has three through holes, the positions of which coincide with the positions of the three sets of flexible cable holes 33, providing space for fixing the flexible cable 522 to the head end of the flexible continuum robotic arm 3.

[0051] Specifically, connecting shafts 421 are symmetrically arranged on the outer wall of the ball seat 42. The two ends of the connecting shaft 421 are connected to the ball seat 42 and the ear plates on one side of the U-shaped ear seat 21 via miniature bearings 422. Specifically, to secure the ball seat 42, stepped holes are designed on the two ear plates of the U-shaped ear seat 21. These stepped holes are used to install the miniature bearings 422 to prevent axial movement of the bearings. Similarly, similar stepped holes are provided on the cylindrical surface of the ball seat 42 for installing the miniature bearings 422. The ball seat 42 is fixed between the two ear plates of the U-shaped ear seat 21 via the connecting shaft 421, allowing it to rotate freely around the connecting shaft 421. This design makes the work platform 2 more flexible and capable of performing more complex movements.

[0052] Furthermore, the robot arm driving mechanism 5 includes a square frame body 501 and a screw-nut mechanism and a flexible cable driving mechanism arranged in the frame body 501 .

[0053] Specifically, such as Figure 10 、 Figure 11 、 Figure 12 、 Figure 13As shown, one end of the frame body 501 is fixedly connected to the stepper motor mounting plate 502, and the other end of the frame body 501 is provided with a continuum mounting plate 505 that is movably connected to the frame body 501. The continuum mounting plate 505 is fixed to the end of the flexible continuum robot arm 3. A servo cylinder mounting plate 503 and a servo cylinder push rod mounting plate 504 are also provided in sequence between the stepper motor mounting plate 502 and the continuum mounting plate 505. The continuum mounting plate 505 and the servo cylinder push rod mounting plate 504 are fixedly connected by a first connecting plate 506, and the servo cylinder push rod mounting plate 504 and the servo cylinder mounting plate 503 are fixedly connected by a second connecting plate 507. The continuum mounting plate 505, the servo cylinder push rod mounting plate 504, and the servo cylinder mounting plate 503 form a component that moves integrally on the lead screw 511.

[0054] The frame 501 includes guide posts 5011 perpendicular to the four corners of the stepper motor mounting plate 502, and a crossbar 5012 connecting two adjacent guide posts 5011. Baffles are installed on the top, front, and back surfaces of the frame 501. Square notches are provided at the four corners of the servo cylinder mounting plate 503, the servo cylinder push rod mounting plate 504, and the continuum mounting plate 505 to allow for clearance of the guide posts 5011. Two sets of first stepper motors 512 are provided, fixed diagonally to the stepper motor mounting plate 502.

[0055] Specifically, the screw-nut mechanism includes a screw 511, one end of which is connected to a first stepper motor 512 fixed on a stepper motor mounting plate 502, and the other end of the screw 511 passes through the stepper motor mounting plate 502, the servo electric cylinder mounting plate 503, the servo electric cylinder push rod mounting plate 504 and the continuum mounting plate 505 in sequence, and a first screw nut 513 that matches the screw 511 is fixed on the continuum mounting plate 505, and a second screw nut 514 and a third screw nut 515 that match the screw 511 are respectively provided on the servo electric cylinder push rod mounting plate 504 and the servo electric cylinder mounting plate 503. The first stepper motor 512 drives the screw 511 to rotate, so that the continuum mounting plate 505 is displaced along the axial direction of the screw 511 to realize the displacement of the flexible continuum robotic arm 3 in the forward and backward directions.

[0056] Specifically, the cable drive mechanism includes a servo cylinder 521 and a cable 522. One end of the cable 522 is fixed to the push rod end of the servo cylinder 521, and the other end of the cable 522 passes through the flexible continuum robot arm 3 and is fixed to the head end of the flexible continuum robot arm 3. Three sets of cables 522 and servo cylinders 521 are provided. The three sets of cables 522, driven by the three sets of servo cylinders 521, respectively, deform the flexible continuum robot arm 3 to achieve pitch and yaw adjustment of the flexible continuum robot arm 3.

[0057] The cylinder end of the servo electric cylinder 521 is fixed to the servo electric cylinder mounting plate 503. The push rod end of the servo electric cylinder 521 passes through the servo electric cylinder push rod mounting plate 504 and is fixed to the flexible cable 522 via the flexible cable connector 523. Preferably, the diameter of the through hole in the servo electric cylinder push rod mounting plate 504 through which the push rod of the servo electric cylinder 521 passes is slightly larger than the diameter of the push rod of the servo electric cylinder 521 to ensure an appropriate clearance fit between the push rod and the hole wall to prevent excessive wear. The flexible cable connector 523 is provided with through holes at each end. The through hole at one end is used to fix the flexible cable 522. The flexible cable 522 is fixed to the flexible cable connector 523 by knotting or adding a metal block. The through hole at the other end is installed with a screw connector 524, which is threadedly connected to the push rod of the servo electric cylinder 521.

[0058] Furthermore, the frame body 501 is fixed to the drive mechanism support frame 6, one end of the drive mechanism support frame 6 is hinged to the top of the support frame 1 via a first hinge 18, and the other end of the drive mechanism support frame 6 is connected to the angle adjustment mechanism 7. In this embodiment, the first hinge 8 is composed of two U-shaped hinges, and the two U-shaped hinges can rotate relative to each other. The upper U-shaped hinge is fixed to the drive mechanism support frame 6, and the lower U-shaped hinge is fixed to the upper triangular frame 11 of the support frame 1. Specifically, a fixed block is fixed in the profile groove of the upper triangular frame 11, and the top of the fixed block is fixed to the lower U-shaped hinge via bolts. Preferably, each side of the upper triangular frame 11 is provided with two fixed blocks, for a total of six fixed blocks, and correspondingly, six first hinges are also provided. The angle adjustment mechanism 7 is provided to add a rotational degree of freedom to the flexible continuum manipulator 3, thereby enabling the entire parallel robot platform to achieve more complex movements. The angle adjustment mechanism 7 is installed between the support frame 1 and the manipulator drive mechanism 5, and can achieve angle adjustment of approximately 0 to 45 degrees.

[0059] Specifically, such as Figure 16 As shown, the angle adjustment mechanism 7 includes a screw-nut slider mechanism and a connecting rod 71. The screw-nut slider mechanism is arranged on the layer 14 of the support frame 1. The layer 14 is rounded at the parts where stress concentration or easy fracture may occur. The screw-nut slider mechanism includes a ball screw 72, a screw-nut seat 73 that cooperates with the ball screw 72, a nut slide 74 fixed to the screw-nut seat 73, and a second stepper motor 75 that drives the ball screw 72 to rotate. The screw-nut slider mechanism also includes slide rails 76 symmetrically arranged on both sides of the ball screw 72, a slide 77 that forms a sliding fit with the slide rail 76, and a connecting bracket 78 fixed to the slide 77. The connecting bracket 78 is fixed to the nut slide 74. The structures not mentioned in the screw-nut slider mechanism can be referred to the existing technology.

[0060] One end of the connecting rod 71 is hinged to the nut slide 74 through the second hinge 711, and the other end of the connecting rod 71 is hinged to the drive mechanism support frame 6 through the third hinge 712. The main body of the connecting rod 71 in this embodiment adopts an "I"-shaped design, which not only reduces the weight of the connecting rod, but also enhances its bending strength. The second hinge 711 and the third hinge 712 are both U-shaped hinges. The connecting rod 71, the drive mechanism support frame 6, the first hinge 18 and the nut slide 74 form a crank slider mechanism. When the second stepper motor 75 drives the nut slide 74 to move along the axial direction of the ball screw 72 through the ball screw 72, the connecting rod 71 drives the drive mechanism support frame 6 to rotate around the hinge axis of the first hinge 18 to achieve the adjustment of the pitch angle of the robot arm drive mechanism 5, and finally achieves the adjustment of the pitch angle of the flexible continuum robot arm 3.

[0061] The working principle of the present invention is as follows:

[0062] 1. The direction of the rope.

[0063] One end of the flexible cable is connected to the push rod end of the servo electric cylinder, and the other end of the flexible cable passes through the continuum mounting plate, the second flange, the flexible continuum mechanical arm and the first flange in sequence and is then fixed on the first flange.

[0064] 2. Working principle of the flexible cable drive mechanism.

[0065] When the servo cylinders are operating, their push rods pull the flexible cables, causing them to expand and contract synchronously. This force is transmitted to the head end of the flexible continuum arm, causing it to deform and drive its movement. Driven by the coordinated action of three servo cylinders, the flexible continuum arm can bend in multiple directions and at specific angles.

[0066] 3. Working principle of screw-nut mechanism.

[0067] The first stepper motor drives the screw to rotate, thereby driving the corresponding continuum mounting plate, servo electric cylinder push rod mounting plate, and servo electric cylinder mounting plate to move synchronously through the first screw nut, the second screw nut, and the third screw nut on the screw, thereby driving the flexible continuum robot arm forward or backward, such as Figure 14 、 Figure 15 shown.

[0068] 4. Working principle of angle adjustment mechanism.

[0069] The second stepper motor drives the ball screw to rotate, thereby driving the nut slide to move through the screw nut seat on the ball screw. When the nut slide moves, the connecting rod will drive the drive mechanism support frame to rotate around the first hinge, thereby realizing the pitch adjustment of the robotic arm drive mechanism.

[0070] In summary, the present invention designs a parallel robot platform based on a composite drive of flexible cables and continuums based on a continuum configuration. The platform consists of three independent continuous motion chains with a total of six degrees of freedom. Each flexible continuum robot arm also introduces additional degrees of freedom of movement and rotation, giving it four degrees of freedom, thereby achieving complex motion of the end effector in space by introducing redundant degrees of freedom. The present invention is highly innovative in the design of continuum robot mechanisms. It not only improves the interactive safety of the robot, but also enhances the accuracy and stability of the end effector while retaining the flexibility of the continuum robot.

[0071] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A parallel robot platform based on a composite drive of flexible cables and continuum, characterized by: The invention comprises a support frame (1) and a working platform (2) suspended above the support frame (1), wherein the working platform (2) is used to connect an end effector; the working platform (2) is evenly provided with three groups of flexible continuum mechanical arms (3) of the same structure along its circumference, the head ends of the three groups of flexible continuum mechanical arms (3) are rotatably connected to the working platform (2) through ball head universal joint assemblies (4), and the ends of the three groups of flexible continuum mechanical arms (3) are respectively connected to a mechanical arm driving mechanism (5); The robotic arm drive mechanism (5) comprises a square frame body (501), a screw nut mechanism and a flexible cable drive mechanism arranged in the frame body (501), one end of the frame body (501) is fixedly connected to the stepper motor mounting plate (502), and the other end of the frame body (501) is provided with a continuum mounting plate (505) movably connected to the frame body (501), and the continuum mounting plate (505) is fixed to the end of the flexible continuum robotic arm (3); The screw-nut mechanism includes a screw (511), one end of the screw (511) is connected to a first stepper motor (512) fixed on a stepper motor mounting plate (502), the other end of the screw (511) passes through the stepper motor mounting plate (502) and the continuum mounting plate (505), and a first screw nut (513) matched with the screw (511) is fixed on the continuum mounting plate (505), and the first stepper motor (512) drives the screw (511) to rotate so as to cause the continuum mounting plate (505) to move along the axial direction of the screw (511) to achieve displacement of the flexible continuum robotic arm (3) in the front-rear direction; The flexible cable drive mechanism comprises a servo electric cylinder (521) and a flexible cable (522), one end of the flexible cable (522) is fixed to the push rod end of the servo electric cylinder (521), and the other end of the flexible cable (522) passes through the flexible continuum mechanical arm (3) and is fixed to the head end of the flexible continuum mechanical arm (3); the flexible cables (522) and the servo electric cylinder (521) are respectively provided in three groups, and the three groups of flexible cables (522) respectively cause the flexible continuum mechanical arm (3) to deform under the driving cooperation of the three groups of servo electric cylinders (521) to achieve pitch and yaw adjustment of the flexible continuum mechanical arm (3); The frame body (501) is fixed on the driving mechanism support frame (6), one end of the driving mechanism support frame (6) is hinged to the top of the support frame (1) through a first hinge (18), and the other end of the driving mechanism support frame (6) is connected to the angle adjustment mechanism (7); The angle adjustment mechanism (7) includes a screw nut slider mechanism and a connecting rod (71), wherein the screw nut slider mechanism is arranged on a layer plate (14) of the support frame (1), and the screw nut slider mechanism includes a ball screw (72), a screw nut seat (73) matched with the ball screw (72), a nut slide plate (74) fixed on the screw nut seat (73), and a second stepping motor (75) for driving the ball screw (72) to rotate; one end of the connecting rod (71) is hinged to the nut slide plate (74) through a second hinge (711). The other end of the connecting rod (71) is hinged to the driving mechanism support frame (6) through a third hinge (712). The connecting rod (71), the driving mechanism support frame (6), the first hinge (18) and the nut slide (74) form a crank slider mechanism. When the second stepping motor (75) drives the nut slide (74) along the axial displacement of the ball screw (72) through the ball screw (72), the connecting rod (71) drives the driving mechanism support frame (6) to rotate around the hinge axis of the first hinge (18) to achieve adjustment of the pitch angle of the robot arm driving mechanism (5).

2. The parallel robot platform based on flexible cable and continuum composite drive according to claim 1 is characterized in that: The screw nut slider mechanism further includes slide rails (76) symmetrically arranged on both sides of the ball screw (72), a slider (77) slidingly matched with the slide rails (76), and a connecting bracket (78) fixed on the slider (77), wherein the connecting bracket (78) is fixed to the nut slider (74).

3. The parallel robot platform based on flexible cable and continuum composite drive according to claim 1 is characterized in that: The supporting frame (1) is a triangular structure as a whole, comprising an upper triangular frame (11), a lower triangular frame (12) and a column (13) connecting the upper triangular frame (11) and the lower triangular frame (12). A layer plate (14) parallel to the upper triangular frame (11) and the lower triangular frame (12) is provided between the upper triangular frame (11) and the lower triangular frame (12). The layer plate (14) is fixed to the column (13) by installing a foot frame (15). The bottom of the lower triangular frame (12) is also covered with a bottom plate (16), and the bottom of the lower triangular frame (12) is also provided with an adjustable foot (17).

4. The parallel robot platform based on flexible cable and continuum composite drive according to claim 1 is characterized in that: The flexible continuum robot arm (3) is a tubular annular continuum of an integral structure, which is formed by connecting multiple identical annular bodies, and each annular body is annularly cut with three equal arcs. One end of the flexible continuum robot arm (3) is connected to the ball head universal joint assembly (4) through a first flange (31), and the other end of the flexible continuum robot arm (3) is fixed to the continuum mounting plate (505) of the robot arm drive mechanism (5) through a second flange (32); the flexible continuum robot arm (3) is evenly provided with three groups of flexible cable holes (33) along its circumference, and the three groups of flexible cable holes (33) are all set through the flexible continuum robot arm (3).

5. The parallel robot platform based on flexible cable and continuum composite drive according to claim 1 is characterized in that: The ball head universal joint assembly (4) includes a ball head rod (41) and a ball head seat (42) that cooperate with each other, the ball head seat (42) is fixed to the working platform (2), and the ball head rod (41) is connected to the flexible continuum robot arm (3) through a connecting piece (43); The connecting member (43) includes a rod-shaped connecting head (431) and a third flange (432), one end of the connecting head (431) is provided with a first threaded hole, and the first threaded hole is matched with the threaded section on the ball head rod (41), the other end of the connecting head (431) is provided with a second threaded hole, and the second threaded hole is fixed to the third flange (432) by a bolt, and the third flange (432) is fixed to the first flange (31) at the end of the flexible continuum robot arm (3).

6. The parallel robot platform based on flexible cable and continuum composite drive according to claim 5 is characterized in that: The working platform (2) is a triangular block structure as a whole, and its three corners respectively form U-shaped ear seats (21) for fixing the ball head seat (42). Connecting shafts (421) are symmetrically arranged on the outer wall of the ball head seat (42), and the two ends of the connecting shaft (421) are respectively connected to the ball head seat (42) and the U-shaped ear seat (21) through micro bearings (422).

7. The parallel robot platform based on flexible cable and continuum composite drive according to claim 1 is characterized in that: A servo electric cylinder mounting plate (503) and a servo electric cylinder push rod mounting plate (504) are sequentially provided between the stepper motor mounting plate (502) and the continuum mounting plate (505), wherein: the continuum mounting plate (505) and the servo electric cylinder push rod mounting plate (504) are fixedly connected via a first connecting plate (506), and the servo electric cylinder push rod mounting plate (504) and the servo electric cylinder mounting plate (503) are fixedly connected via a second connecting plate (507), and the servo electric cylinder push rod mounting plate (504) and the servo electric cylinder mounting plate (503) are respectively provided with a second screw nut (514) and a third screw nut (515) that match the screw rod (511), and the continuum mounting plate (505), the servo electric cylinder push rod mounting plate (504), and the servo electric cylinder mounting plate (503) form a component that moves as a whole on the screw rod (511).

8. The parallel robot platform based on flexible cable and continuum composite drive according to claim 7, characterized in that: The cylinder end of the servo electric cylinder (521) is fixed on the servo electric cylinder mounting plate (503), and the push rod end of the servo electric cylinder (521) passes through the servo electric cylinder push rod mounting plate (504) and is fixed to the flexible rope (522) through a flexible rope connector (523); through holes are respectively provided at both ends of the flexible rope connector (523), wherein the through hole at one end is used to fix the flexible rope (522), and a screw joint (524) is installed at the through hole at the other end, and the screw joint (524) is threadedly connected to the push rod of the servo electric cylinder (521).

9. The parallel robot platform based on flexible cable and continuum composite drive according to claim 7, characterized in that: The frame body (501) includes guide columns (5011) arranged at the four corners perpendicular to the stepper motor mounting plate (502) and a crossbar (5012) connecting two adjacent guide columns (5011). The four corners of the servo electric cylinder mounting plate (503), the servo electric cylinder push rod mounting plate (504) and the continuum mounting plate (505) are respectively provided with square notches for avoiding the guide columns (5011). Two groups of the first stepper motors (512) are provided, and the two groups of first stepper motors (512) are fixed on the stepper motor mounting plate (502) in a diagonal direction.

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