A distributed drive tensegrity multi-arm robot

Abstract

The present invention belongs to the technical field of multi-arm machines, and specifically relates to a distributed drive tensegrity multi-arm robot, comprising a mounting base; two or more tensegrity flexible manipulator arms are mounted on the mounting base, each manipulator arm being composed of a plurality of modular drive segments connected together; the modular drive segments being composed of a drive device connected to a tensegrity arm body. Each modular drive segment is driven in a segmented manner, each drive segment being equipped with an independent driver, enabling independent motion control of each drive segment, thereby providing the manipulator arm with flexible motion capabilities. Each drive segment contains only two drivers, one of which realizes axial rotation of the arm segment and one of which drives bending of the arm body. Compared with conventional drive methods, this reduces one driver without sacrificing the manipulator arm's flexibility.

Description

Technical Field

[0001] The present invention belongs to the technical field of multi-arm machines, and in particular relates to a distributed-drive tensegrity multi-arm robot. Background Art

[0002] Robots now play an important role in various industries and fields. In recent decades, people have worked hard to explore robots working in complex environments outside of factories, such as the development of medical robots, sweeping robots, space robots, etc. In some unstructured environments, the role of continuous flexible manipulators has been explored, such as exploration tasks in confined areas, disaster relief work, and the capture and recovery of space debris. To this end, researchers have proposed a variety of continuous manipulator arm designs, which generally have flexible deformation capabilities and soft arms. Due to its ability to continuously deform, the manipulator can not only perform exploration tasks in confined areas, but also use its arm to wrap around objects to achieve flexible capture.

[0003] Due to its rigid-flexible coupling characteristics, tensegrity structures have been applied to the design of continuous manipulators, demonstrating excellent performance. A tensegrity structure is a self-balancing structure formed by the action of tension on rigid and tensile elements. The tensile elements are typically elastic elements such as ropes and springs. Using tensile elements to actuate the structure's deformation is the most common method. Many tensegrity manipulators employ an external drive system, with servos installed at the base and then driven by ropes. This system achieves a higher stiffness-to-mass ratio. This drive system requires at least three motors to control the bending of the manipulator in any direction. However, using three servos only allows for a single bending motion of the manipulator in a specific direction. To ensure greater flexibility, more actuators are generally required, resulting in a larger and more complex drive mechanism at the base of the manipulator. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes a distributed drive tensegrity multi-arm robot, which adopts a segmented drive method. Each drive segment is equipped with an independent driver, which can realize independent motion control of each drive segment, so that the operating arm has flexible movement capabilities, and each drive segment contains only two drivers, one of which realizes the axial rotation of the arm body and the other is used to drive the bending of the arm body. Compared with the general drive method, one driver is reduced without losing the flexibility of the operating arm.

[0005] In order to achieve the above object, the present invention is achieved through the following technical solutions:

[0006] A distributed drive tensegrity multi-arm robot comprises a mounting base;

[0007] Two or more tensegrity flexible operating arms are mounted on the mounting base, each operating arm being composed of a plurality of modular drive segments connected together;

[0008] The modular drive section is formed by connecting a drive device and a tensegrity arm body;

[0009] The arm body is composed of a plurality of Y-shaped connecting frames connected by springs. Springs are installed symmetrically in the longitudinal direction between two adjacent Y-shaped connecting frames, and an odd number of springs are installed at equal intervals in the radial direction to form a self-balancing tensegrity structure. A plurality of drive ropes are passed through each Y-shaped connecting frame. The ends of the drive ropes are connected to the drive device. The pulling of the drive ropes causes the arm body to generate bending and deformation movement.

[0010] The driving device includes a rotation driving module and a rope driving module. The rotation driving module drives the entire arm to rotate axially; the rope driving module controls the driving rope through the winch to drive the arm to bend. The rotation driving module and the rope driving module are respectively driven by a servo.

[0011] Preferably, the Y-shaped connecting frame includes a three-dimensional Y-shaped bracket and a circular ring connected to its top, four rope holes are equidistantly arranged on the circumference of the circular ring, four outer spring slots are equidistantly connected to the outer circumference of the circular ring, and three inner spring slots are also equidistantly connected to the upper surface of the circular ring and the bottom of the three-dimensional Y-shaped bracket.

[0012] Preferably, an external connecting spring connection is provided between the corresponding external spring slots between the two adjacent Y-shaped connecting frames, and an internal connecting spring connection is provided between the upper surface of the circular ring of one of the two adjacent Y-shaped connecting frames and the internal spring slot at the bottom of the other Y-shaped connecting frame.

[0013] Preferably, four driving ropes are passed through the four rope holes, two adjacent driving ropes are pull ropes, and the other two are loose ropes. One end of the driving rope is fixedly connected to the winch, and the other end is fixedly connected to the rope hole of the last Y-shaped connecting frame.

[0014] Preferably, the rotation drive module includes an arc-shaped bracket having the same circular ring as the Y-shaped connecting frame, a spring slot and a rope threading hole. A single-axis servo is installed in the circular ring through a servo mounting platform. The rotating shaft of the single-axis servo is connected to the center of the rotating disk, and four bearings are equidistantly arranged on the outer circumference of the rotating disk. The outer circumference of the rotating disk is embedded in the groove of the bearing. The bearing is fixed on the back of the servo mounting platform. The bearing fixes the rotating disk while reducing the rotational friction.

[0015] Preferably, the rope drive module includes a U-shaped connecting seat installed on a rotating disc, a dual-axis servo is installed in the U-shaped connecting seat, winches are respectively installed on the two rotating shafts of the dual-axis servo, and arm connecting frames are also installed on both sides of the dual-axis motor. The top of the arm connecting frame is also provided with a circular ring, spring slot and rope threading hole that are the same as those of the Y-shaped connecting frame.

[0016] Preferably, the winch is designed as two tracks with different radii, wherein the track with a larger radius is used for collecting the rope, and the track with a smaller radius is used for releasing the rope.

[0017] Preferably, a pulley is installed at the position of the rope threading hole corresponding to the last Y-shaped connecting frame. After the driving rope comes out of the winch, it passes through the rope threading hole of the arm connecting frame and the rope threading holes of each Y-shaped connecting frame, and then passes around the pulley on the last Y-shaped connecting frame, and then passes through the rope threading holes of each Y-shaped connecting frame in turn, and finally is connected and fixed to the arm connecting frame.

[0018] The beneficial effects of the present invention are:

[0019] (1) The operating arm adopts a segmented drive mode, and each driving segment is equipped with an independent driver, which can realize independent motion control of each driving segment, thus making the operating arm have flexible movement capabilities;

[0020] (2) Each drive segment contains only two actuators, one of which realizes the axial rotation of the arm segment and the other is used to drive the arm body to bend. Compared with the general drive method, one actuator is reduced without losing the flexibility of the operating arm;

[0021] (3) A pulley is installed at the position corresponding to the rope hole of the last Y-type connecting frame. After the driving rope comes out of the winch, it passes through the rope hole of the arm connecting frame and the rope hole of each Y-type connecting frame, and then passes around the pulley on the last Y-type connecting frame, and then passes through the rope hole of each Y-type connecting frame in turn, and finally is connected and fixed on the arm connecting frame. Here, the pulley plays the role of a movable pulley, which can save more effort and reduce the load of the driving servo.

[0022] (4) Four bearings are arranged at equal intervals on the outer circumference of the rotating disk. The outer circumference of the rotating disk is embedded in the groove of the bearings. The bearings are fixed on the back of the servo mounting platform. The bearings fix the rotating disk and reduce the rotational friction, which not only ensures the stable connection of the components but also reduces the rotational friction. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 Schematic diagram of the overall structure of the multi-arm robot in the embodiment;

[0025] Figure 2 Schematic diagram of the modular arm structure of the multi-arm robot in the embodiment;

[0026] Figure 3 Schematic diagram of the Y-shaped connecting frame structure of the multi-arm robot in the embodiment;

[0027] Figure 4 Schematic diagram of the driving device structure of the multi-arm robot in the embodiment;

[0028] Figure 5 Schematic diagram of the rotation drive module structure of the multi-arm robot in the embodiment;

[0029] Figure 6 This is a schematic diagram of the structure of a rotating disc installed on the rotation drive module of the multi-arm robot in the embodiment;

[0030] Figure 7 This is a structural diagram of a rope drive module installed on a rotating disc of a multi-arm robot in an embodiment;

[0031] Figure 8 Schematic diagram of the structure of the rope drive module and the arm body connecting frame of the multi-arm robot in the embodiment;

[0032] Figure 9 Schematic diagram of the connection structure of the driving rope of the driving pulley of the multi-arm robot in the embodiment;

[0033] Figure 10 Schematic diagram of the connection structure between the driving device and the arm body of the multi-arm robot in the embodiment;

[0034] Figure 11 Schematic diagram of the O-shaped bending deformation structure of the dual-drive segment operating arms of the multi-arm robot in the embodiment;

[0035] Figure 12 Schematic diagram of the S-shaped bending deformation structure of the dual-drive segment operating arm of the multi-arm robot in the embodiment;

[0036] Figure 13 Schematic diagram of the three-dimensional bending deformation structure of the dual-drive segment operating arm of the multi-arm robot in the embodiment.

[0037] In the accompanying drawings, the structural names represented by the reference numerals are:

[0038] 10-operating arm, 1-Y-type connecting frame, 101-Y-type bracket, 102-ring, 103-rope hole, 104-external spring slot, 105-inner spring slot, 2-external connecting spring, 3-inner connecting spring, 4-drive rope, 5-drive device, 501-rotation drive module, 5011-arc bracket, 5012-servo mounting platform, 5013-single-axis servo, 5014-bearing, 5015-rotating disc, 502-rope drive module, 5021-dual-axis servo, 5022-U-type connecting seat, 5023-winch, 6-arm connecting frame, 7-pulley, 20-mounting base. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0040] Example

[0041] A distributed drive tensegrity multi-arm robot, such as Figure 1 As shown, it includes four tensegrity flexible manipulator arms 10, each composed of several modular drive segments. The four manipulator arms 10 are evenly mounted on a rectangular mounting base 20 and can move in coordination with each other, thereby achieving multi-arm entanglement and capture of space debris.

[0042] like Figure 2 As shown, the modular drive segment includes a drive device 5 and a tensegrity arm. Each drive device 5 consists of two parts: a rotation drive module 501 and a rope drive module 502. The rotation drive module 501 drives the arm segment and its rear end segment axially, thereby achieving spatial motion of the manipulator arm 10. The rope drive module 502 controls the drive rope 4 via a winch 5023 to drive the arm bending. The tensegrity arm is composed of several Y-shaped connecting frames 1 connected by springs. Under the tension of the springs, the arm achieves a self-balancing state.

[0043] like Figure 3 As shown, the Y-shaped connecting frame 1 that makes up the tensegrity arm includes four rope holes 103, four outer spring slots 104, three top inner spring slots 105, and three bottom inner spring slots 105. The rope holes 103 are four holes that penetrate the top circular ring 102 and are evenly spaced at 90° intervals on the ring 102. They are used to restrain the drive rope 4 while providing driving force. The outer spring slots 104 are used to connect to the longitudinal outer connecting spring 2. They protrude outward from the top circular ring 102 and are staggered at 45° with the rope holes 103. The top inner spring slots 105 are used to connect to the inner connecting spring 3, and are then connected to the bottom inner spring slots 105 of the adjacent Y-shaped connecting frame 1.

[0044] The tensegrity arm is composed of a Y-shaped connector 1 and tension springs, which are connected via slots in the Y-shaped connector 1. Four springs are mounted longitudinally between two adjacent Y-shaped connectors 1, and three springs are mounted radially, forming a self-balancing tensegrity structure. Bending motion is generated by pulling a drive rope 4 through a rope hole 103.

[0045] The tensegrity arm is driven by four drive ropes 4, two of which are pull ropes and two are loose ropes, so that the arm can be deflected to the side of the pull ropes.

[0046] See Figure 4 As shown, the drive device 5 consists of two parts: a rotation drive module 501 and a rope drive module 502. The rotation drive module 501 drives the rope drive module 4 to rotate axially, thereby driving the entire arm body to rotate; the rope drive module 502 controls the drive rope 4 via a winch 5023 to drive the arm body to bend. The rotation drive module 501 and the rope drive module 502 are each driven by a servo. The rotation drive module 501 is equipped with a single-axis servo 5013, while the rope drive module 502 is equipped with a dual-axis servo 5021. Unlike a conventional dual-axis servo 5021, which only has one side that can actively output torque and the other side that only passively rotates, the dual-axis servo 5021 used here can output torque on both axes simultaneously, thereby simultaneously driving two winches 5023 and better driving four drive ropes 4.

[0047] like Figures 5 and 6 As shown, specifically, the rotation drive module 501 includes: a single-axis servo 5013, a servo mounting platform 5012, four H-shaped bearings 5014, and an arc-shaped bracket 5011. The arc-shaped bracket 5011 has the same circular ring 102, spring slot, and rope threading hole 103 as the Y-shaped connecting frame 1. The difference is that the tripod support structure below is U-shaped instead of Y-shaped. The purpose is to reserve sufficient installation space for the single-axis servo 5013 and reduce the overall size. The rotating axis of the single-axis servo 5013 is connected to the center of the rotating disk 5015, and four bearings 5014 are equidistantly arranged on the outer circumference of the rotating disk 5015. The outer circumference of the rotating disk 5015 is embedded in the grooves of the bearings 5014. The bearings 5014 are fixed to the back of the servo mounting platform 5012. The bearings 5014 fix the rotating disk 5015 and reduce rotational friction.

[0048] like Figures 7 and 8As shown, the cable drive module includes a U-shaped connector 5022 mounted on a rotating disk 5015. A dual-axis steering gear 5021 is installed within the U-shaped connector 5022. A capstan 5023 is mounted on each of the two rotating shafts of the dual-axis steering gear 5021. An arm connector 6 is also mounted on either side of the dual-axis motor. The top of the arm connector 6 is also provided with a circular ring 102, a spring retaining groove, and a rope threading hole 103, similar to those of the Y-shaped connector 1. Because the amount of rope contraction during arm bending is different from the amount of rope extension, the rope extension is generally greater. Therefore, the capstan 5023 is designed with two tracks of different radii, with the larger track used for rope retraction and the smaller track used for rope release. This approach avoids the phenomenon of the drive rope 4 becoming slack. While this approach only allows the operating arm 10 to bend to one side, the rotary drive module 501 overcomes this shortcoming. Under the action of the rotary drive module 501, the arm only needs to be able to bend to one side to achieve the three-dimensional motion capability of the entire drive module.

[0049] The driving rope 4 of a typical rope-driven continuous manipulator 10 is generally directly connected to a rigid body at the end, such as Figure 9 As shown, in the present invention, the pulley 7 is installed at the position of the rope threading hole 103 of the last Y-shaped connecting frame 1. After the driving rope 4 comes out of the winch 5023, it passes through the rope threading hole 103 of the arm connecting frame 6 and the rope threading holes 103 of each Y-shaped connecting frame 1, and then passes through the pulley 7 on the last Y-shaped connecting frame 1, and then passes through the rope threading holes 103 of each Y-shaped connecting frame 1 in turn, and finally is connected and fixed to the arm connecting frame 6.

[0050] like Figure 10 As shown, the short operating arm 10 in the figure has two unit components, which clearly shows the configuration of one section of the operating arm 10. More unit components can be added on this basis to increase the length of one section of the operating arm 10. The black line is the position of the rope. The figure shows two ropes on a winding drum, which are wound in opposite ways and placed in their respective tracks. The bending effect in the figure is the result of the winding drum rotating counterclockwise at a certain angle.

[0051] like Figure 11As shown, by combining several modular drive segments in series, a complete continuous operating arm 10 can be obtained. It can be seen that the operating arm 10 of the present invention does not have a bulky and complex root drive device 5, and does not involve a complex transmission mechanism. Through the segmented drive method, the operating arm 10 can be bent into an O shape as shown in the figure, which can achieve the winding of objects with a small radius. In addition, the general root drive connects the drive rope 4 from the root to the end of the operating arm 10. When the drive is deformed, the drive rope 4 needs to transmit the driving force to the farther end, resulting in a larger driving force required for the drive rope 4, and the requirements for the driver are also relatively high. The present invention adopts a segmented drive method, and the transmission distance of the driving force of the drive rope 4 is shorter, and the requirements for the driving force are also lower.

[0052] like Figure 12 and Figure 13 As shown, in addition to the aforementioned O-shape, the operating arm 10 can also achieve S-shape and three-dimensional deformation by rotating the rotary drive module 501 of the second drive section. Thus, flexible deformation of the operating arm 10 is achieved with relatively few drivers.

[0053] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. The preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification.

Claims

1. A distributed drive tensegrity multi-arm robot, comprising a mounting base (20), characterized in that: Two or more tensegrity flexible operating arms (10) are installed on the mounting base (20), and each operating arm (10) is composed of a plurality of modular drive segments connected together; The modular drive section is formed by connecting a drive device (5) and a tensegrity arm body; The arm body is composed of a plurality of Y-shaped connecting frames (1) connected by springs, springs are longitudinally symmetrically installed between two adjacent Y-shaped connecting frames (1), and an odd number of springs are radially and circumferentially equidistantly installed to form a self-balancing tensile structure, a plurality of driving ropes (4) are passed through each Y-shaped connecting frame (1), and the ends of the driving ropes (4) are connected to the driving device (5), and the pulling of the driving ropes (4) causes the arm body to generate bending deformation movement; The Y-shaped connecting frame (1) comprises a three-dimensional Y-shaped bracket (101) and a circular ring (102) connected to the top thereof, four rope threading holes (103) are uniformly spaced through the circumference of the circular ring (102), four outer spring clamping grooves (104) are uniformly connected to the outer circumference of the circular ring (102), and three inner spring clamping grooves (105) are also uniformly spaced on the upper surface of the circular ring (102) and the bottom of the three-dimensional Y-shaped bracket (101); The driving device (5) comprises a rotation driving module (501) and a rope driving module (502). The rotation driving module (501) drives the entire arm body to perform axial rotation. The rope driving module (502) controls the driving rope (4) via a winch (5023) to drive the arm body to bend. The rotation driving module (501) and the rope driving module (502) are each driven by a steering gear. The rotary drive module (501) comprises an arc-shaped bracket (5011) having the same circular ring (102) and spring clamping groove and rope threading hole (103) as the Y-shaped connecting frame (1); a single-axis servo (5013) is installed in the circular ring (102) via a servo mounting platform (5012); the rotating shaft of the single-axis servo (5013) is connected to the center of a rotating disc (5015); four bearings (5014) are equidistantly arranged on the outer circumference of the rotating disc (5015); the outer circumference of the rotating disc (5015) is embedded in the groove of the bearing (5014); the bearing (5014) is fixed to the back of the servo mounting platform (5012); the bearing (5014) fixes the rotating disc (5015) and reduces the rotational friction; The rope drive module (502) comprises a U-shaped connecting seat (5022) mounted on a rotating disc (5015), a dual-axis steering gear (5021) mounted in the U-shaped connecting seat (5022), winches (5023) mounted on the two rotating shafts of the dual-axis steering gear (5021), and an arm connecting frame (6) mounted on both sides of the dual-axis motor. The top of the arm connecting frame (6) is also provided with a circular ring (102), a spring slot and a rope threading hole (103) similar to those of the Y-shaped connecting frame (1).

2. The distributed drive tensegrity multi-arm robot according to claim 1, characterized in that: An external connection spring (2) is provided between the corresponding external spring slots (104) between the two adjacent Y-shaped connection frames (1), and an internal connection spring (3) is provided between the upper surface of the ring (102) of one of the two adjacent Y-shaped connection frames (1) and the internal spring slot (105) at the bottom of the other Y-shaped connection frame (1).

3. The distributed drive tensegrity multi-arm robot according to claim 2, characterized in that: Four driving ropes (4) are passed through the four rope-threading holes (103), wherein two adjacent driving ropes (4) are pull ropes and the other two are loose ropes. One end of the driving rope (4) is fixedly connected to the winch (5023), and the other end is fixedly connected to the rope-threading hole (103) of the last Y-shaped connecting frame (1).

4. The distributed drive tensegrity multi-arm robot according to claim 3, characterized in that: The winch (5023) is designed as two tracks with different radii, wherein the track with a larger radius is used for collecting the rope, and the track with a smaller radius is used for loosening the rope.

5. The distributed drive tensegrity multi-arm robot according to claim 4, characterized in that: The pulley (7) is installed at the position of the rope threading hole (103) corresponding to the last Y-shaped connecting frame (1). After the driving rope (4) comes out of the winch (5023), it passes through the rope threading hole (103) of the arm connecting frame (6) and the rope threading holes (103) of each Y-shaped connecting frame (1), and then passes around the pulley (7) on the last Y-shaped connecting frame (1), and then passes through the rope threading holes (103) of each Y-shaped connecting frame (1) in sequence, and finally is connected and fixed on the arm connecting frame (6).

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