Line-driven flexible mechanical arm

Abstract

A line-driven flexible mechanical arm comprises a chassis, a plurality of sections of lower half limbs and a plurality of sections of upper half limbs. The chassis is provided with a first steering engine and a second steering engine which are perpendicular to each other and drive the pull wire shaft to take up and pay off the drive wire. A clamping plate locking mechanism controlled by a steering engine III is arranged in the lower half limb; the upper half limb and the lower half limb are connected through a universal joint; in the working process, the chassis steering engines integrally take up and pay off the driving lines, the three steering engines independently control the clamping plates to be loosened and tightened, local locking or releasing of the driving lines is achieved, and therefore independent or cooperative movement of the joints is completed; the structure has the advantages of high-degree-of-freedom flexible motion capability, light-weight far-end driving, multi-section decoupling control, modular expansion, low cost, high reliability and the like, and is suitable for the fields of bionic robots, medical intervention, pipeline detection and the like.

Description

Technical Field

[0001] This invention relates to the field of robotic arm technology, and more specifically to a line-driven flexible robotic arm. Background Technology

[0002] Currently, multi-axis robotic arms are developing rapidly and are widely used in existing scenarios. However, existing robotic arms suffer from difficulties in performing complex movements and biomimetic challenges. Patent application CN111589362A discloses a rope-driven continuous robotic arm, consisting of multiple disc joints connected by a flexible spine, with three or four drive ropes distributed circumferentially and winding back to the base motor from the end. Spatial bending is achieved through differential rope retraction and extension. However, it suffers from severe motion crosstalk. All segments share the same set of drive ropes, and pulling one rope simultaneously causes multiple segments to bend. It is impossible to control a single segment individually, only achieving overall arc-shaped bending, thus limiting degrees of freedom. Once the motor stops, the joints, lacking self-locking or clamping devices, are easily subjected to external forces to rebound or become unstable, making it difficult to maintain a specific configuration. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention aims to propose a wire-driven flexible robotic arm. It integrates several servo motors and a pull-wire shaft, employing a wire-driven, multi-segment flexible joint, and independent wire-locking mechanism integrated design. This effectively solves key problems of existing robotic arms, such as difficulty in biomimicry, bulky structure, and control coupling, achieving high-degree-of-freedom flexible motion capabilities. It boasts advantages such as lightweight design and remote drive; multi-segment independent and precise control; low cost and high reliability. Applicable to cutting-edge fields with high requirements for compliance, compactness, and safety, such as biomimetic robots, medical interventional devices, pipeline inspection, and disaster search and rescue, this invention has outstanding practical value and promising prospects for widespread application.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A wire-driven flexible robotic arm includes a chassis, multiple lower limbs, and multiple upper limbs; The chassis includes a support base 1, on which are mounted servo motor 3 and servo motor 8, which are perpendicular to each other in axis. The output shaft of servo motor 3 is connected to cable shaft 6 via coupling 4, and the output shaft of servo motor 8 is connected to cable shaft 11 via coupling 9. The lower limb includes a lower limb base 12 fixed on the support 1. Each of the lower limb base 12 has a lower limb boss 13 in the cross direction on the top surface of the lower limb base 12. The lower limb boss 13 is provided with a locking plate 14. The top and bottom of the locking plate 14 are adapted to the corresponding sliding grooves 31 provided in the lower limb boss 13. The outer edge of the locking plate 14 is axially connected to one end of the connecting rod 15. The other end of the connecting rod 15 is axially connected to the cross rotating plate 16. The center of the cross rotating plate 16 is connected to the output shaft of the servo motor 17 provided in the center of the lower limb base 12. The upper limb includes an upper limb base 18 and an upper limb boss 19 fixed in a cross direction on the bottom surface of the upper limb base 18. Each upper limb boss 19 in the cross direction is provided with a universal joint 20 connecting the upper limb base 18 and the lower limb base 12.

[0005] The pull-line shaft 6 is provided with a spool connection hole 21 and a spool connection hole 22. The lower limb base 12 is provided with a lower base connection hole 29 and a lower base connection hole 30. The lower limb boss 13 is provided with a lower limb connection hole 23 and a lower limb connection hole 24. The upper limb base 18 is provided with an upper base connection hole 25 and an upper base connection hole 26. The upper limb boss 19 is provided with an upper limb connection hole 27 and an upper limb connection hole 28. The pull-line shaft 6 is connected by a wire passing through the spool connection hole 21, the lower base connection hole 29, the lower limb connection hole 23, and the upper limb... The connection holes are 27, 25, 26, 28, 24, and 30, and 22, which are connected to the spool connection hole on the pull shaft 6. A drive wire passes through the spool connection hole 21, 29, 23, 27, 25, 26, 28, 24, and 30 in sequence, and is finally fixed to the spool connection hole 22, forming a closed-loop wire path.

[0006] The servo motor 3 drives the pull shaft 6 to rotate, thereby retracting and extending the drive cable, which in turn drives the coordinated movement of the upper and lower limbs.

[0007] When the clamping plate 14 is in the proximal state, it clamps the drive line passing through the lower limb protrusion 13 to lock the joint; when the clamping plate 14 is in the centrifugal state, it releases the drive line, allowing the joint to move freely.

[0008] The multiple lower limbs and multiple upper limbs are connected in series to form a multi-segment flexible arm. By independently controlling the locking or releasing state of the drive lines of the servo motors 17 in each segment, combined with the overall retraction and extension of the drive lines of the chassis servo motor, the independent or coordinated movement of each joint can be achieved, thereby completing complex bionic movements.

[0009] Robots or devices, including those consisting of the aforementioned line-driven flexible robotic arm structures.

[0010] Based on the above technical solution, the beneficial effects of the present invention are as follows: 1. Achieve complex biomimetic movements, breaking through the limitations of traditional robotic arm motion. Traditional multi-axis robotic arms typically consist of multiple rigid links and rotary / linear joints connected in series, resulting in limited degrees of freedom and weak coupling between joint movements. This makes it difficult to replicate the continuous bending, twisting, and other high-degree-of-freedom flexible movements of biological limbs (such as elephant trunks, snakes, and arms). This invention connects multiple upper and lower limb segments via universal joints, each independently controlled by a cable. This enables the entire arm to possess continuous deformation capabilities, allowing for bending, stretching, and even helical movements in any direction in space. This significantly improves the robotic arm's motion flexibility and biomimetic capabilities, making it suitable for scenarios requiring precise and compliant operation (such as minimally invasive surgery, confined space exploration, and human-computer interaction).

[0011] 2. Utilizing a wire-driven approach to achieve lightweight design and remote operation. Traditional joints require each segment to have a built-in motor, reducer, and other drive units, resulting in high weight, high inertia, and a bulky structure, especially when multiple segments are connected in series. Furthermore, motor heat and electromagnetic interference limit their application in specific environments (such as MRI rooms). In this invention, all drive sources (servo motor one, servo motor two, and servo motor three) are centrally located on the chassis, and power is remotely transmitted to each joint segment via steel wire rope wound around a pull-coil. The joint body itself has no motor, containing only passive mechanisms such as locking plates, connecting rods, and cross-shaped rotating plates.

[0012] Significantly reduces end-effector mass, lowers motion inertia, and improves response speed; simplifies joint structure, facilitating miniaturization and modular design; avoids end-effector electromagnetic interference, expanding application areas (such as medical and precision instrument operation).

[0013] 3. Innovative clamping-releasing mechanism enables independent control of multiple sections. Wire-driven systems often face the "crosstalk problem"—pulling a single wire can affect multiple joints, making independent control of each joint difficult. This invention addresses this issue by incorporating a wire locking mechanism in the lower half of each joint, consisting of a servo motor, a cross-shaped rotating plate, a connecting rod, and a locking plate. When control of a particular joint is needed, the corresponding locking plate releases, allowing the wire to slide; the locking plates of the remaining joints lock, fixing the wire position and thus isolating movement. This solves the motion coupling problem in wire-driven systems, enabling decoupled control of multiple joints and making complex trajectory planning possible.

[0014] 4. Modular structure, facilitating expansion and maintenance. In this invention, the upper and lower limbs are connected by universal joints and bosses, and the number of limbs can be flexibly increased or decreased according to task requirements; the cable path passes through the central hole of the boss, resulting in neat wiring that is not easily tangled; in case of failure, a single module can be replaced without overall disassembly. This improves the system's reconfigurability, maintainability, and adaptability.

[0015] 5. Low cost and high reliability The core driving components of this invention consist of only a few servo motors and cable shafts, resulting in significantly lower hardware costs compared to multi-motor solutions. The wire drive eliminates gear wear and lubrication requirements, simplifying maintenance and extending service life. Even if some cables slack, the remaining joints can still function, demonstrating a degree of fault tolerance. It is suitable for large-scale deployments or resource-constrained scenarios (such as education, agriculture, and disaster relief).

[0016] In summary, this invention, through the integrated design of wire drive, multi-segment flexible joints, and independent wire locking mechanisms, effectively solves key problems of existing robotic arms, such as difficulty in biomimicry, bulky structure, and control coupling. It achieves: high-degree-of-freedom flexible motion capabilities; lightweight design and remote-controlled advantages; independent and precise control of multiple segments; and low cost and high reliability. Therefore, this wire-driven flexible robotic arm is particularly suitable for cutting-edge fields with high requirements for compliance, compactness, and safety, such as biomimetic robots, medical interventional devices, pipeline inspection, and disaster search and rescue, and has outstanding practical value and promising prospects for widespread application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the bottom structure of the present invention; Figure 3 A cross-sectional view of the connection structure between the cross plate 16, the connecting rod 15 and the clamping plate 14; Figure 4 This is a schematic diagram of the single-section structure of the present invention after the base is removed; Figure 5 This is a schematic diagram showing the connection between the upper and lower limb structures of the present invention; Figure 6 This is a schematic diagram of the single-segment lower limb structure after removing the chassis according to the present invention; Figure 7 This is a schematic diagram of the structure of the present invention during operation.

[0019] In the diagram: 1. Base; 2. Support component one; 3. Servo motor one; 4. Coupling one; 5. Bearing one; 6. Cable pull shaft one; 7. Support component two; 8. Servo motor two; 9. Coupling two; 10. Bearing two; 11. Cable pull shaft two; 12. Lower limb base; 13. Lower limb boss; 14. Clamping plate; 15. Connecting rod; 16. Cross rotating plate; 17. Servo motor three; 18. Upper limb base; 19. Upper limb boss; 20. Universal joint; 21. Spool connection hole one; 22. Spool connection hole two; 23. Lower limb connection hole one; 24. Lower limb connection hole two; 25. Upper base connection hole one; 26. Upper base connection hole two; 27. Upper limb connection hole one; 28. Upper limb connection hole two; 29. ​​Lower base connection hole one; 30. Lower base connection hole two; 31. Slide groove. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] See Figures 1 to 7 A line-driven flexible robotic arm includes a chassis, multiple lower limbs, and multiple upper limbs; See Figure 2 The chassis includes a support base 1, on which are mounted servo motor 3 and servo motor 8, which are perpendicular to each other in axis; the output shaft of servo motor 3 is connected to cable shaft 6 via coupling 4, and the output shaft of servo motor 8 is connected to cable shaft 11 via coupling 9. See Figure 2 , Figure 3 The lower limb includes a lower limb base 12 fixed on the support base 1. Each of the lower limb base 12 has a lower limb boss 13 in the cross direction on the top surface of the lower limb base 12. The lower limb boss 13 is provided with a retaining plate 14. The top and bottom of the retaining plate 14 are adapted to the corresponding sliding groove 31 provided in the lower limb boss 13. The outer edge of the retaining plate 14 is axially connected to one end of the connecting rod 15. The other end of the connecting rod 15 is axially connected to the cross rotating plate 16. The center of the cross rotating plate 16 is connected to the output shaft of the servo motor 17 provided in the center of the lower limb base 12. See Figure 4 The upper limb includes an upper limb base 18 and an upper limb boss 19 fixed in a cross direction on the bottom surface of the upper limb base 18. Each upper limb boss 19 in the cross direction is provided with a universal joint 20 connecting the upper limb base 18 and the lower limb base 12.

[0022] See Figures 4 to 6 The pull-line shaft 6 is provided with a spool connection hole 21 and a spool connection hole 22. The lower limb base 12 is provided with a lower base connection hole 29 and a lower base connection hole 30. The lower limb boss 13 is provided with a lower limb connection hole 23 and a lower limb connection hole 24. The upper limb base 18 is provided with an upper base connection hole 25 and an upper base connection hole 26. The upper limb boss 19 is provided with an upper limb connection hole 27 and an upper limb connection hole 28. The pull-line shaft 6 is connected by a wire passing through the spool connection hole 21, the lower base connection hole 29, the lower limb connection hole 23, and the upper limb connection hole 24. The upper limb connection hole 27, the upper base connection hole 25, the upper base connection hole 26, the upper limb connection hole 28, the lower limb connection hole 24, the lower limb connection hole 20, and the spool connection hole 22 on the pull wire shaft 6 are connected; a drive wire passes through the spool connection hole 21, the lower base connection hole 29, the lower limb connection hole 23, the upper limb connection hole 27, the upper base connection hole 25, the upper base connection hole 26, the upper limb connection hole 28, the lower limb connection hole 24, and the lower base connection hole 20 in sequence, and is finally fixed to the spool connection hole 22, forming a closed loop wire path.

[0023] The servo motor 3 drives the pull shaft 6 to rotate, thereby retracting and extending the drive cable, which in turn drives the coordinated movement of the upper and lower limbs.

[0024] When the clamping plate 14 is in the proximal state, it clamps the drive line passing through the lower limb protrusion 13 to lock the joint; when the clamping plate 14 is in the centrifugal state, it releases the drive line, allowing the joint to move freely.

[0025] The multiple lower limbs and multiple upper limbs are connected in series to form a multi-segment flexible arm. By independently controlling the locking or releasing state of the drive lines of the servo motors 17 in each segment, combined with the overall retraction and extension of the drive lines of the chassis servo motor, the independent or coordinated movement of each joint can be achieved, thereby completing complex bionic movements.

[0026] The servo motor 17 drives the cross plate 16 to rotate, which in turn drives the connecting rod 15 to move, thereby controlling the clamping plate 14 to perform centrifugal or proximal motion in the radial direction. The upper limb base 18 and the lower limb base 12 are connected by a universal joint 20, so that the upper limb can rotate with multiple degrees of freedom relative to the lower limb within a certain angle range, thereby achieving flexible bending motion.

[0027] See Figure 7 The number of upper and lower limbs can be set by the user.

[0028] By utilizing the stretchable properties of the line, and the rotation of the winding shaft driven by servo motor one and servo motor two, the line can be stretched and extended. At the same time, the cross plate driven by servo motor three controls the clamping and releasing of the line passing through each upper and lower limb, thereby achieving independent motion control of different joints.

[0029] The working principle of this invention is as follows: See Figures 1 to 7 The flexible robotic arm is composed of multiple articulated units connected in series. Each unit includes an upper limb 1, a lower limb 2, and a universal joint 3 connecting the two. All drive sources are centrally located on the chassis 4, including servo motor 1 5, servo motor 2 6, and multiple servo motors 3 7.

[0030] The pull shaft 8 is mounted on the chassis 4 and driven by either servo motor 5 or servo motor 6. The steel wire pull cable 9 wound on it passes through the center hole 10 of each section boss and is connected at the end to the traction point of the upper half limb 1 of the corresponding section. When the servo motor rotates, the pull shaft 8 retracts or expands the steel wire pull cable 9, pulling the upper half limb 1 to deflect relative to the lower half limb 2 around the universal joint 3, achieving local bending.

[0031] Each lower limb segment 2 is equipped with a locking plate 11, a connecting rod 12, and a cross plate 13, which are controlled by the corresponding servo motor 7. When a certain segment needs to move, the servo motor 7 of that segment drives the cross plate 13 → connecting rod 12 → releases the locking plate 11, allowing the steel wire pull cable 9 to slide. The locking plates 11 of the remaining segments remain locked to fix the position of the pull cable and prevent motion interference.

[0032] By coordinating and controlling each servo motor, the entire arm can continuously bend, extend, or spiral in three-dimensional space, achieving biomimetic flexible operation.

[0033] The line-driven flexible robotic arm structure described in this invention can be applied to robots or equipment.

[0034] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0035] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A line-driven flexible robotic arm, characterized in that, It includes a chassis, multiple lower limbs, and multiple upper limbs; The chassis includes a support base (1), on which are mounted servo motor 1 (3) and servo motor 2 (8) that are perpendicular to each other. The output shaft of servo motor 1 (3) is connected to pull wire shaft 1 (6) via coupling 1 (4), and the output shaft of servo motor 2 (8) is connected to pull wire shaft 2 (11) via coupling 2 (9). The lower limb includes a lower limb base (12) fixed on a support base (1). Each of the lower limb base (12) has a lower limb boss (13) in the cross direction on the top surface of the lower limb base (12). A card plate (14) is provided in the lower limb boss (13). The top and bottom of the card plate (14) are adapted to the corresponding sliding groove (31) in the lower limb boss (13). The outer edge of the card plate (14) is axially connected to one end of the connecting rod (15). The other end of the connecting rod (15) is axially connected to the cross rotating plate (16). The center of the cross rotating plate (16) is connected to the output shaft of the servo motor three (17) set in the center of the lower limb base (12). The upper limb includes an upper limb base (18) and an upper limb boss (19) fixed in the cross direction on the bottom surface of the upper limb base (18). Each upper limb boss (19) in the cross direction is provided with a universal joint (20) connecting the upper limb base (18) and the lower limb base (12).

2. The line-driven flexible robotic arm according to claim 1, characterized in that, The pull shaft 1 (6) is provided with a spool connection hole 1 (21) and a spool connection hole 2 (22). The lower limb base (12) is provided with a lower base connection hole 1 (29) and a lower base connection hole 2 (30). The lower limb boss (13) is provided with a lower limb connection hole 1 (23) and a lower limb connection hole 2 (24). The upper limb base (18) is provided with an upper base connection hole 1 (25) and an upper base connection hole 2 (26). The upper limb boss (19) is provided with an upper limb connection hole 1 (27) and an upper limb connection hole 2 (28). The pull shaft 1 (6) passes through the spool connection hole 1 (21), the lower base connection hole 1 (29), the lower limb connection hole 1 (23), and the upper limb connection hole 2 (28). Connecting hole 1 (27), upper base connecting hole 1 (25), upper base connecting hole 2 (26), upper limb connecting hole 2 (28), lower limb connecting hole 2 (24), lower limb connecting hole 2 (30) and spool connecting hole 2 (22) on pull wire shaft 1 (6) are connected; a drive wire passes through spool connecting hole 1 (21), lower base connecting hole 1 (29), lower limb connecting hole 1 (23), upper limb connecting hole 1 (27), upper base connecting hole 1 (25), upper base connecting hole 2 (26), upper limb connecting hole 2 (28), lower limb connecting hole 2 (24), lower base connecting hole 2 (30) in sequence, and is finally fixed to spool connecting hole 2 (22) to form a closed loop wire path.

3. The line-driven flexible robotic arm according to claim 1, characterized in that, The servo motor (3) rotates by driving the pull shaft (6) to retract and extend the drive line, thereby driving the coordinated movement of multiple upper and lower limbs.

4. The line-driven flexible robotic arm according to claim 1, characterized in that, When the clamping plate (14) is in the proximal state, it clamps the drive line passing through the protrusion (13) of the lower limb, thereby locking the joint; when the clamping plate (14) is in the centrifugal state, it releases the drive line, allowing the joint to move freely.

5. A line-driven flexible robotic arm according to claim 1, characterized in that, The multiple lower limbs and multiple upper limbs are connected in series to form a multi-segment flexible arm. By independently controlling the locking or releasing state of the drive line of the servo motor three (17) in each segment, combined with the overall retraction and extension of the drive line of the chassis servo motor, the independent or coordinated movement of each joint can be realized, thereby completing complex bionic movements.

6. A robot or device, including any of the line-driven flexible robotic arms described in claims 1 to 5.

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