A tensegrity manipulator with selective differential mechanism

Abstract

The present invention discloses a tensegrity manipulator with a selective differential mechanism, relating to the field of robotics. The manipulator comprises tensegrity fingers, a palm baseplate, and a selective differential mechanism. The tensegrity fingers are divided into three-jointed fingers and two-jointed fingers, each finger being composed of a plurality of phalange modules connected in series via elastic cords. The phalange modules include phalanges, angle sensors, connecting shafts, and wire lockers. The tensegrity fingers are connected to the palm baseplate via connectors. The selective differential mechanism is provided on the palm baseplate and is used to drive the tensegrity fingers. The manipulator of the present invention combines the advantages of a tensegrity structure and a differential mechanism, achieving a lightweight design while enabling individual control of each finger and exhibiting excellent flexibility.

Description

Technical Field

[0001] The present invention relates to the field of robotics technology, and in particular to a tensegrity manipulator with a selective differential mechanism. Background Art

[0002] With the continuous development of industrial technology and the increasing demand for healthcare services, people are placing higher demands on the performance of robotic arms, especially in terms of dexterity, lightweight, and human-like performance. However, traditional robotic arms are mostly designed using an all-wheel drive configuration. While this approach achieves a high degree of freedom, it also brings problems such as system complexity, large size and weight, and high control difficulty.

[0003] Tensegrity structures offer a new approach to solving these problems. Tensegrity structures are stable, self-balancing structures composed of compression and tension members, characterized by structural flexibility and lightweight construction. The stiffness of these structures is provided by the balanced prestress between the tension and compression elements, resulting in virtually no stiffness before prestressing. Tensegrity structures are already widely used in the construction industry. Furthermore, their mechanical properties and controllability make them promising for applications in aerospace, biomimetic machinery, and other fields.

[0004] The differential mechanism provides an optimized solution for the manipulator's drive system. It decomposes the DC motor's input motion into multiple distinct motions, reducing the number of components required in the drive system. This design not only helps reduce the manipulator's weight but also simplifies the control logic, improving system reliability and flexibility.

[0005] Combining tensegrity and differential mechanisms in manipulator design can fully leverage the advantages of both. The tensegrity structure provides the manipulator with greater flexibility and lightweight properties, making it more adaptable in complex environments. The differential mechanism, on the other hand, optimizes the drive system and reduces the manipulator's complexity. This combination is expected to not only enhance the manipulator's overall performance but also provide new directions for future robotic design. Summary of the Invention

[0006] The purpose of the present invention is to provide a tensegrity manipulator with a selective differential mechanism to solve the problems of large size and weight and complex control of traditional manipulators.

[0007] To achieve the above-mentioned object, the present invention provides the following solution: a tensegrity manipulator with a selective differential mechanism, comprising:

[0008] Tensegrity fingers are divided into three-joint fingers and two-joint fingers. Each finger is composed of several phalange modules connected in series via elastic ropes. The phalange modules include phalanges, angle sensors, connecting shafts, and wire lockers. The three-joint fingers include distal phalange modules, middle phalange modules, proximal phalange modules, and metacarpal modules. The three-joint fingers serve as the index finger, middle finger, ring finger, and pinky finger of the robot, while the two-joint fingers serve as the thumb of the robot.

[0009] a palm base plate, the tensegrity fingers being connected to the palm base plate via connectors;

[0010] a selective differential mechanism, the selective differential mechanism being provided on the palm base plate and being used to drive the tensegrity finger movements; the selective differential mechanism comprising a pulley assembly, an electromagnetic locking device, a second DC motor, and first, second, and third drive ropes provided on the palm base plate;

[0011] The pulley assembly includes a plurality of fixed pulleys and movable pulleys provided on the palm base plate. The palm base plate is provided with a plurality of pins, which are rotatably connected to wire posts as fixed pulleys. Two linear guide sliders are slidably provided on the palm base plate, and the linear guide sliders are connected to plug screws as movable pulleys.

[0012] The electromagnetic locking device includes an electromagnet and a winding wheel. The electromagnet extends or shortens its shaft end by turning on and off the power supply. When the electromagnet is powered off, the protrusion of the winding wheel is blocked by the shaft end of the electromagnet, and the winding wheel cannot rotate, thereby locking the movement of the corresponding three-joint finger.

[0013] One end of the driving rope 2 and the driving rope 3 are respectively fixedly connected to the distal phalanx modules of the little finger and the middle finger, and after being wound several times on the corresponding winding wheels, they pass through the screws on the corresponding linear guide sliders. The other end is respectively wound several times on the winding wheels corresponding to the ring finger and index finger and then fixedly connected to the distal phalanx modules of the ring finger and index finger; one end of the driving rope 1 is fixed to the DC motor 2, and after passing through the screws on the two linear guides, the other end is also fixed to the DC motor 2.

[0014] The above structure aims to propose a tensegrity manipulator with a selective differential mechanism, which combines the advantages of the tensegrity structure and the differential mechanism to achieve a lightweight design while being able to individually control each finger and having good flexibility.

[0015] Optionally, the selective differential mechanism further comprises a servo for driving the thumb to perform palm-to-palm movement.

[0016] Optionally, the two-joint finger includes a distal phalanx module, a middle phalanx module and a metacarpal module.

[0017] Optionally, one end of the second and third drive ropes is fixed to the distal phalanx module, and the other end passes through the wire holes of the middle phalanx module, the proximal phalanx module, and the metacarpal module in sequence to reach the selective differential mechanism.

[0018] Optionally, the proximal phalanx module and the middle phalanx module have the same structure and both include a phalanx body, a connecting shaft is provided at the upper end of the phalanx body, and a wire locker is provided at the lower end, the connecting shaft is interference fit with the angle sensor, and a small hole is opened on the connecting shaft to connect two adjacent phalanx modules through an elastic rope.

[0019] Optionally, one end of the two elastic ropes is fixed to the connecting shaft, and the other end is respectively connected to the upper phalange module and the wire locker of the upper phalange module; one end of the other elastic rope is connected to the wire locker of the current phalange module, and the other end is connected to the lower phalange module.

[0020] Optionally, the angle sensor adopts a linear potentiometer, and the joint angle is obtained by measuring the voltage at its output end, thereby realizing real-time monitoring of the finger joint angle.

[0021] The present invention discloses the following technical effects:

[0022] Compared with traditional manipulators, the present invention introduces a tensegrity structure, and the unique connection method makes the joints of the manipulator have the advantages of simple structure, smooth movement, light weight and easy control.

[0023] This invention replicates the coordinated control of a human hand through a selective differential mechanism, rather than relying on DC motors to independently drive each joint like in traditional manipulators. By coordinating the motion of multiple joints, this approach reduces independent control variables, speeding up the manipulator controller and minimizing control delays.

[0024] The present invention can lock the movement of specific fingers and implement different driving schemes according to different task requirements, thereby flexibly controlling the structure with more than 20 degrees of freedom of movement and completing a variety of daily functional tasks.

[0025] The present invention has the advantage of being constructed as a multi-level structure. It can not only form a humanoid robot hand by constructing a four-level structure of distal finger joint-middle finger joint-proximal finger joint-palm, but also can form a multi-joint bionic animal or robot arm structure by connecting the tensegrity joint and the selective differential mechanism in series and parallel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in 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 paying any creative work.

[0027] Figure 1 2. A structural diagram of a tensegrity manipulator with a selective differential mechanism according to an embodiment of the present invention;

[0028] Figure 2 Schematic diagram of the structure of the proximal phalanx module in an embodiment of the present invention;

[0029] Figure 3 This is a schematic structural diagram of a three-joint finger in an embodiment of the present invention;

[0030] Figure 4 Schematic diagram of the structure of the selective differential mechanism in an embodiment of the present invention;

[0031] Figure 5 Schematic diagram of the connection of the selective differential mechanism in an embodiment of the present invention.

[0032] In the figure: 1. distal phalanx module; 2. middle phalanx module; 3. proximal phalanx module; 4. metacarpal module; 5. two-jointed finger; 6. selective differential mechanism; 7. drive rope 1; 8. drive rope 2; 9. drive rope 3; 10. palm base plate; 301. phalanx body; 302. angle sensor; 303. elastic rope 1; 304. connecting shaft; 305. elastic rope 2; 306. wire locker; 307. elastic rope 3; 501. DC motor 1; 601. winding wheel; 602. linear guide slider; 603. plug screw; 604. DC motor 2; 605. wire column; 606. electromagnet; 607. servo. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Reference Figures 1 to 5As shown, the present invention provides a tensegrity manipulator with a selective differential mechanism. The manipulator is mainly composed of tensegrity fingers, a selective differential mechanism 6, and connectors. Tensegrity fingers are divided into three-joint fingers and two-joint fingers 5. Each finger is composed of phalange modules connected in series. The phalange module is the basic unit of the finger and includes phalanges, angle sensors 302, connecting shafts 304, and wire locks 306. The phalanges serve as supporting structures, the connecting shafts 304 are used to connect adjacent phalange modules, and the wire locks 306 are used to secure the elastic rope. The angle sensor 302 uses a linear potentiometer. The joint angle is converted by measuring the voltage at its output end, thereby achieving real-time monitoring of the finger joint angle.

[0036] In this embodiment, four phalangeal modules are connected in sequence with elastic ropes to form a three-joint finger, and three phalangeal modules are connected in sequence with elastic ropes to form a two-joint finger 5. The present invention uses the two-joint finger 5 as the thumb of the robot and the three-joint finger as the index finger, middle finger, ring finger and little finger of the robot.

[0037] In this embodiment, the structure and assembly of the tensegrity finger are as follows:

[0038] The structure and assembly of three-jointed fingers are as follows Figure 3 As shown, the proximal phalanx module 3 has the same structure as the middle phalanx module 2. Taking the structure of the proximal phalanx module 3 as an example, the proximal phalanx module 3 includes a phalanx body 301, a connecting shaft 304 at the upper end, and a thread locker 306 at the lower end. The connecting shaft 304 is interference-fitted with the angle sensor 302, and a small hole is formed in the connecting shaft 304 to connect two adjacent phalanx modules via elastic cords. One end of each elastic cord is fixed to the connecting shaft 304, and the other end is connected to the thread locker 306 of the upper phalanx module and the upper phalanx module, respectively. One end of the other elastic cord is connected to the thread locker 306 of the current phalanx module and the other end is connected to the lower phalanx module. When the finger bends and deforms, the elastic cord is stretched to store elastic potential energy. When the driving cord is released, the finger returns to its initial state under the tension of the elastic cord.

[0039] The two-jointed finger 5 is composed of three phalangeal modules connected in sequence by elastic ropes; the two-jointed finger 5 serves as the thumb of the manipulator, and its structure is similar to that of the three-jointed finger, but it only contains two joints; the joints of the thumb are driven by a DC motor 501 to achieve independent control of the thumb.

[0040] The three-jointed fingers serve as the index, middle, ring, and pinky fingers of the robot, while the two-jointed finger 5 serves as the thumb. Each finger is connected to the palm base plate 10 via connectors, forming a complete finger portion of the robot. One end of the drive rope is fixed to the distal phalanx module 1, and the other end passes through the wire holes of the middle phalanx module 2, the proximal phalanx module 3, and the metacarpal module 4, before reaching the selective differential mechanism 6 in the palm. When the DC motor 604 drives the selective differential mechanism 6, the drive rope contracts, causing the fingers to deform, thus achieving coupled motion similar to that of a human finger.

[0041] In this embodiment, if Figure 4 As shown, the selective differential mechanism 6 primarily consists of a pulley assembly, an electromagnetic locking device, and a second DC motor 604. The selective differential mechanism 6 is mounted on the palm base 10. Specifically, the palm base 10 is equipped with a pulley assembly, a winding wheel 601, an electromagnet 606, a second DC motor 604, and two linear guides. Two linear guide sliders 602 slide on each of the linear guides, each of which is mounted with a driving screw 603. The pulley assembly transmits power from the drive rope, the electromagnetic locking device locks the movement of individual fingers, and the second DC motor 604 provides the power to drive the movement of the fingers. The second DC motor 604 drives the pulley assembly via the drive rope, which in turn drives the fingers via the drive rope. The electromagnetic locking device locks the movement of individual fingers, enabling the manipulator to individually control each finger. The electromagnet 606 can extend or shorten the shaft end by turning the power on and off. After the driving rope passes through the wire hole of the metacarpal module 4, it is wound around the winding wheel 601 for several turns. When the electromagnet 606 is powered off, the protrusion of the winding wheel 601 will be blocked by the shaft end of the electromagnet 606 and cannot rotate, thereby locking the corresponding finger.

[0042] The electromagnetic device includes an electromagnet 606 and a winding wheel 601. Electromagnet 606 can extend or contract its shaft end by switching on and off. When electromagnet 606 is de-energized, the protrusion of winding wheel 601 is blocked by the shaft end of electromagnet 606, preventing it from rotating and thus locking the corresponding finger's movement. When electromagnet 606 is energized, the shaft end retracts, allowing winding wheel 601 to rotate freely, and the finger can move under the drive rope.

[0043] The DC motor 2 604 drives the pulley set to move through the driving rope, thereby achieving the bending and stretching of the fingers. Figure 4 As shown, the DC motor 2 604 is responsible for driving the four fingers except the thumb, and the servo 607 is fixed to the palm base plate 10 for driving the thumb to perform palm-to-palm movement.

[0044] The overall assembly and functional implementation of the manipulator structure described above involves sequentially connecting the index finger, middle finger, ring finger, and pinky finger to the palm base plate 10, connecting the thumb to the servo 607 on the palm base plate 10, and routing the drive ropes that control finger bending along a pulley system. This constitutes the tensegrity manipulator designed by the present invention with a selective differential mechanism. Based on the physiological characteristics of the human hand, the present invention enables functions such as single-finger pinching, two-finger pinching, radial pinching, and envelope grasping. Through the selective differential mechanism 6, the movement of each finger can be individually controlled, enabling complex grasping and manipulation tasks.

[0045] In a specific embodiment, Figure 2 As shown, connecting shaft 304 is interference-fitted with angle sensor 302. A small hole is provided in connecting shaft 304 to allow elastic cords to connect two adjacent phalanges. Elastic cords 1 and 2, 305, are fixed to connecting shaft 304 at one end. Elastic cord 1 303 and elastic cord 2 305 each have one end connected to the upper phalange, while elastic cord 2 305 has the other end connected to the thread lock 306 of the upper phalange module. Elastic cord 3 307, another elastic cord, has one end connected to the thread lock 306 of the current phalange and the other end connected to the lower phalange. When the finger bends and deforms, this elastic cord stretches, storing elastic potential energy. When the driving cord is released, the finger returns to its initial position under the tension of this elastic cord.

[0046] In a specific embodiment, Figure 3 As shown, the four phalangeal modules are connected in the above manner to form a three-jointed finger. It should be noted that the distal phalangeal module 1 does not require the angle sensor 302, and the metacarpal module 4 does not require the wire lock 306. One end of the drive rope is fixed to the distal phalangeal module 1, and the other end is passed through the wire holes of the middle phalangeal module 2, the proximal phalangeal module 3, and the metacarpal module 4 in sequence before reaching the differential mechanism in the palm. When the DC motor 2 604 drives the differential mechanism, the drive rope contracts, causing the finger to deform, thereby achieving coupled motion similar to that of a human finger. The proximal phalangeal module 3 is removed, and the resulting two-jointed finger 5 serves as the thumb of the manipulator. The joints of this thumb are driven by a DC motor 1 501.

[0047] In a specific embodiment, Figure 4 and Figure 5As shown, one end of drive rope 2 (8) and drive rope 3 (9) are respectively attached to the distal phalanx modules 1 of the pinky and middle fingers. After being wound several times on their corresponding winding reels 601, they pass through the screws 603 on the corresponding linear guide sliders 602. The other ends are then wound several times on the corresponding winding reels 601 of the ring and index fingers, respectively, before being fixed to the distal phalanx modules 1 of the ring and index fingers. A hole is drilled in the wire post 605 on the palm base 10, and a pin is inserted into it to serve as a fixed pulley, acting as a conductor. The drive rope is passed through the screws 603 on the two linear guide sliders 602, simulating the function of a movable pulley. One end of drive rope 1 (7) is fixed to DC motor 2 (604). After passing through the screws 603 on the two linear guides, the other end is also fixed to DC motor 2 (604). The rotation of DC motor 2 (604) causes drive rope 1 (7) to contract, causing the linear guides to move, which in turn drives drive rope 2 (8) and drive rope 3 (9), causing the fingers to bend. The DC motor 1 501 drives the thumb, the DC motor 2 604 drives the four fingers except the thumb, and the servo 607 is fixed to the palm base plate 10 and drives the entire thumb to perform palm-to-palm movement.

[0048] Any details not provided in the present invention are all conventional technical means well known to those skilled in the art.

[0049] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0050] The embodiments described above are merely descriptions of preferred embodiments 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 persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A tensegrity manipulator with a selective differential mechanism, characterized in that: include: Tensegmental fingers, the tensegmental fingers are divided into three-joint fingers and two-joint fingers (5), each finger is composed of a plurality of phalange modules connected in series via elastic ropes, the phalange modules comprising phalanges, angle sensors (302), connecting shafts (304) and wire lockers (306); the three-joint fingers comprise a distal phalange module (1), a middle phalange module (2), a proximal phalange module (3) and a metacarpal module (4); the three-joint fingers serve as the index finger, middle finger, ring finger and little finger of the manipulator, and the two-joint fingers (5) serve as the thumb of the manipulator; A palm base plate (10), wherein the tensegrity-type fingers are connected to the palm base plate (10) via a connecting piece; A selective differential mechanism (6), the selective differential mechanism (6) being provided on the palm base plate (10) and being used for driving the tensegrity-type finger movement; the selective differential mechanism (6) comprising a pulley set provided on the palm base plate (10), an electromagnetic locking device, a second DC motor (604), and a first drive rope (7), a second drive rope (8), and a third drive rope (9); The pulley assembly includes a plurality of fixed pulleys and movable pulleys provided on the palm base plate (10), the palm base plate (10) is provided with a plurality of pins, the pins are rotatably connected to the wire rods (605) as fixed pulleys, two linear guide sliders (602) are slidably provided on the palm base plate (10), and the linear guide sliders (602) are connected to the plug screws (603) as movable pulleys; The electromagnetic locking device comprises an electromagnet (606) and a winding wheel (601), wherein the electromagnet (606) extends or shortens its shaft end by powering on and off, and when the electromagnet (606) is powered off, the protrusion of the winding wheel (601) is blocked by the shaft end of the electromagnet (606), and the winding wheel (601) cannot rotate, thereby locking the movement of the corresponding three-joint finger; One end of the second driving rope (8) and the third driving rope (9) are respectively fixed to the distal phalanx modules (1) of the little finger and the middle finger, and after being wound several times on the corresponding winding wheels (601), they pass through the screws (603) on the corresponding linear guide sliders (602). The other end is respectively wound several times on the corresponding winding wheels (601) of the ring finger and the index finger, and then fixedly connected to the distal phalanx modules (1) of the ring finger and the index finger; one end of the first driving rope (7) is fixed to the second DC motor (604), and after passing through the screws (603) on the two linear guides, the other end is also fixed to the second DC motor (604).

2. The tensegrity manipulator with a selective differential mechanism according to claim 1, characterized in that: The selective differential mechanism (6) further comprises a steering engine (607) for driving the thumb to perform palm-to-palm movement.

3. The tensegrity manipulator with a selective differential mechanism according to claim 2, characterized in that: The two-joint finger (5) comprises a distal phalanx module (1), a middle phalanx module (2) and a metacarpal module (4).

4. The tensegrity manipulator with a selective differential mechanism according to claim 3, characterized in that: One end of the second drive rope (8) and the third drive rope (9) is fixed to the distal phalanx module (1), and the other end passes through the wire holes of the middle phalanx module (2), the proximal phalanx module (3), and the metacarpal module (4) in sequence and then reaches the selective differential mechanism (6).

5. The tensegrity manipulator with a selective differential mechanism according to claim 3, characterized in that: The proximal phalanx module (3) and the middle phalanx module (2) have the same structure, both comprising a phalanx body (301), a connecting shaft (304) being provided at the upper end of the phalanx body (301), and a wire locker (306) being provided at the lower end, the connecting shaft (304) being interference-fitted with the angle sensor (302), and a small hole being provided on the connecting shaft (304) so ​​as to connect two adjacent phalanx modules via an elastic rope.

6. The tensegrity manipulator with a selective differential mechanism according to claim 5, characterized in that: One end of the two elastic ropes is fixed to the connecting shaft (304), and the other end is connected to the upper phalange module and the wire locker (306) of the upper phalange module respectively; one end of the other elastic rope is connected to the wire locker (306) of the current phalange module, and the other end is connected to the lower phalange module.

7. The tensegrity manipulator with a selective differential mechanism according to claim 1 or 5, characterized in that: The angle sensor (302) adopts a linear potentiometer, and the joint rotation angle is obtained by measuring the voltage at its output end, thereby achieving real-time monitoring of the finger joint angle.

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