Flexible joint underactuated rope-driven snake-arm

Abstract

The application provides a flexible joint underactuated rope-driven snake-shaped arm, and belongs to the field of mechanical arms. The application solves the problems of traditional mechanical arms, such as easy damage under stress, complex structure, large size and inability to complete a wrapping operation. The flexible joint underactuated rope-driven snake-shaped arm comprises a plurality of sequentially rotating joints, the fixed included angle between the axis and the rotating direction of each adjacent two joints is used to make the whole joints in a spiral shape for realizing the wrapping operation on an object. Each adjacent two joints are connected through a flexible connecting piece. A rope is arranged in a group of channels, the end of each rope in the group of channels is inserted into the rope hole of the first end joint, sequentially passes through the rope holes of adjacent joints and is fixed on the middle joint, the end of each rope in another group of channels is inserted into the rope hole of the first end joint, sequentially passes through the rope holes of adjacent joints and is fixed on the end joint. A base is arranged, the first end joint is connected with the base. An upper computer is arranged, and all the rope driving assemblies are electrically connected with the upper computer. The flexible joint underactuated rope-driven snake-shaped arm is mainly used for grabbing operation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of mechanical arm, in particular to a flexible joint underactuated rope-driven snake arm. BACKGROUND

[0002] Rope-driven mechanical arm generally contains multiple series joints and uses ropes to simulate biological tendons for driving. Unlike motor-driven mode, the driving components of rope-driven mechanical arm are generally installed at the base, and the arm body part can reduce the design size and reduce the structure weight, so it can be applied in narrow environments such as space station cabin, nuclear power station interior or aircraft fuel tank interior. At the same time, because the arm body is a pure mechanical structure, it does not need to consider the influence of vacuum, extreme temperature and thermal radiation on electronic devices, and the application scene is wide. According to the geometric configuration characteristics of rope-driven mechanical arm, this kind of mechanical arm can be called rope-driven snake arm and bionic tentacle, etc.

[0003] The joint connection structure of traditional mechanical arm generally adopts rigid components, and the stress generated by structural deformation in the contact collision scene is large, which is easy to cause destructive effect on the structure. In addition, the number of ropes of general rope-driven mechanical arm is greater than the number of degrees of freedom of the mechanism, and there are problems such as complex structure and large size. SUMMARY

[0004] Therefore, the present application aims to provide a flexible joint underactuated rope-driven snake arm to solve the problems of traditional mechanical arm that is easy to be damaged under stress, complex structure, large size and unable to complete the wrapping action.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical scheme: a flexible joint underactuated rope-driven snake arm, comprising:

[0006] A plurality of sequentially rotating joints, the axis of rotation of each adjacent two joints and the rotation direction form a fixed angle, so that all the joints are in a spiral shape as a whole for wrapping operation on an object. Each adjacent two joints are connected by a flexible connecting piece, and two groups of channels symmetrically distributed on both sides of the joint rotation axis are arranged on each joint, and a plurality of rope holes are arranged in each group of channels;

[0007] Ropes, one-to-one corresponding to all rope holes and less than the number of degrees of freedom of all joints, the end of each rope in one group of channels is inserted into the rope hole of the first end joint, sequentially passes through the rope hole of the adjacent joint, and is fixed on the middle joint, and the end of each rope in the other group of channels is inserted into the rope hole of the first end joint, sequentially passes through the rope hole of the adjacent joint, and is fixed on the end joint;

[0008] A base, a rope driving assembly corresponding to all the ropes is arranged on the base for driving each rope to move, and the first end joint is connected to the base;

[0009] The host computer is electrically connected with all the rope driving assemblies.

[0010] Further, the joints are vertebrae.

[0011] Further, the vertebrae are provided with data line holes.

[0012] Further, the flexible connecting piece is a flexible leaf spring, which comprises a connecting part and a bending part, and the connecting part is provided with two ends connected with the bending part respectively, and each connecting part is connected with a corresponding joint.

[0013] Further, the flexible connecting piece is in a Z shape as a whole.

[0014] Further, the snake-shaped arm further comprises a visual camera, which is electrically connected with the host computer.

[0015] Further, the rope driving assembly comprises a lead screw module and a DC motor, the rotating end of the DC motor is connected with the rotating input end of the lead screw module, and the movable end of the lead screw module is connected with the first end of the corresponding rope.

[0016] Further, the base is provided with a pitch motor, the base is connected with the first end joint through the output end of the pitch motor, and the pitch motor is electrically connected with the host computer.

[0017] Further, the base is provided with a yaw motor for controlling the turning of the base, and the yaw motor is electrically connected with the host computer.

[0018] Further, the number of joints is 36, and the number of ropes is 4.

[0019] Compared with the prior art, the beneficial effects of the present application are:

[0020] 1. The snake-shaped arm uses an under-actuated mode to complete the simplification of the structure under the premise of meeting the normal driving, so that the structure size is reduced, and the whole snake-shaped arm is more portable.

[0021] 2. The whole snake-shaped arm is in a spiral configuration, which can realize the covering operation of the object and complete the work that the traditional mechanical arm cannot complete.

[0022] 3. The snake-shaped arm adopts a Z-shaped flexible leaf spring structure composed of a connecting section and a bending section, which is simple and practical, can increase the passive flexibility of the snake-shaped arm, increase the carrying capacity, and cooperate with the ropes to make the snake-shaped arm perform flexible actions, and the flexibility of the flexible connecting piece and the cooperation with the ropes make the under-actuated mode possible.

[0023] 4、The serpentine arm can complete more complex actions through the driving of the pitch motor and the compliant action of itself, so that the serpentine arm can work at any angle and in any working condition. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings, which form a part of the present application, are intended to provide further understanding of the present application and are incorporated herein for a purpose of explanations. The illustrative embodiments of the present application, as well as the explanations thereof, are intended to explain the present application and are not intended to limit the present application. In the drawings:

[0025] Figure 1 A flexible joint underactuated rope-driven serpentine arm in a straight state according to the present application;

[0026] Figure 2 A structural schematic diagram of a flexible joint underactuated rope-driven serpentine arm according to the present application;

[0027] Figure 3 A structural schematic diagram of a vertebra according to the present application;

[0028] Figure 4 A structural schematic diagram of a flexible connecting piece according to the present application.

[0029] Vertebra 1, data line hole 1-1, rope hole 1-2, flexible leaf spring 2, connecting part 2-1, bending part 2-2, rope 3, visual camera 4, base 5, lead screw module 6, direct current motor 7, pitch motor 8, yaw motor 9. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only some of the embodiments of the present application, but not all the embodiments.

[0031] With reference to the accompanying drawings, a flexible joint underactuated rope-driven serpentine arm according to the present embodiment comprises:

[0032] A plurality of sequentially rotating joints, the axis of rotation of each adjacent two of the joints has a fixed angle with the direction of rotation, so that all the joints are in a spiral shape as a whole for the object to achieve the wrapping operation. Each adjacent two of the joints are connected by a flexible connecting piece, and two groups of channels symmetrically distributed on each of the joints are provided, and a plurality of rope holes 1-2 are arranged in each group of channels; due to the fact that the axis of rotation of adjacent joints is at a certain angle with the direction of rotation, so that all the joints are in a spiral shape as a whole, the spiral structure as a whole can perform wrapping type actions and can maintain a certain stability, and at the same time, the flexible connecting piece can ensure a certain flexibility between each adjacent two joints, prevent damage and have the toughness to maintain a certain form, and can meet the requirements of different use conditions.

[0033] Rope 3, which is provided in one-to-one correspondence with all the rope holes 1-2 and in a number less than the number of joint degrees of freedom, the end of each of the ropes 3 in one group of channels is inserted into the rope hole 1-2 of the first end joint, sequentially passes through the rope hole 1-2 of the adjacent joint, and is fixed on the middle joint, and the end of each of the ropes 3 in the other group of channels is inserted into the rope hole 1-2 of the first end joint, sequentially passes through the rope hole 1-2 of the adjacent joint, and is fixed on the end joint; the setting of the rope 3 can drive the whole snake-shaped arm, and at the same time, the setting mode in which the number is less than the number of joint degrees of freedom can reduce the weight and the complexity of the structure, and through the cooperation with the flexible connecting piece, the flexibility between each adjacent two joints can be maintained, so that the under-actuated mode with a reduced number of ropes 3 is possible. The mode that the ropes 3 in one group of channels are fixed on the middle joint and the other group of ropes 3 are fixed on the end joint can drive the snake-shaped arm in two parts as a whole, so that it can complete more complex flexible actions and broaden the application scenarios of the snake-shaped arm.

[0034] Visual camera 4, fixed on the end joint; the setting of the visual camera 4 can measure the position and posture of the end of the snake-shaped arm, and is convenient for the user to understand the use state of the snake-shaped arm.

[0035] Base 5, which is provided with a rope driving assembly corresponding to all the ropes 3 for driving each of the ropes 3 to act, and the first end joint is connected with the base 5; the setting of the base 5 can provide a mounting position for the snake-shaped arm.

[0036] Host computer, the visual camera 4 and all the rope driving assemblies are electrically connected with the host computer. The host computer can control the visual camera 4 and the rope driving assembly, so as to complete the corresponding action according to the instruction.

[0037] In the embodiment, the joint is the vertebra 1. The whole body has a certain inclined conical structure, which facilitates the spiral movement of the snake-shaped arm, so that the snake-shaped arm can complete the wrapping action.

[0038] In the embodiment, the vertebra 1 is provided with a data line hole 1-1. The data line can pass through the data line hole 1-1, which does not affect the completion of the corresponding action of the snake-shaped arm and does not cause interference phenomenon, thereby facilitating the stability of the working state of the snake-shaped arm.

[0039] In the embodiment, the flexible connecting piece is a flexible leaf spring 2, which includes a connecting part 2-1 and a bending part 2-2. The connecting part 2-1 is provided with two and is connected at both ends of the bending part 2-2 respectively. Each connecting part 2-1 is connected with the joint at the corresponding position. The bending part 2-2 can make the whole flexible connecting piece have a certain toughness, and the connecting part 2-1 plays a role in connecting the joint.

[0040] In the embodiment, the flexible connecting piece has a Z shape. This structure is different from the general torsional spring, spring and other structures, which can well adapt to the stress state of the snake-shaped arm during the ring wrapping, has strong torsional resistance, and makes the reliability of maintaining the wrapping action under the driving of the rope 3.

[0041] In the embodiment, the material of the flexible leaf spring 2 is spring steel 65Mn. The service life and fatigue strength are increased.

[0042] In the embodiment, the rope driving assembly includes a lead screw module 6 and a DC motor 7. The rotating end of the DC motor 7 is connected with the rotating input end of the lead screw module 6. The movable end of the lead screw module 6 is connected with the first end of the corresponding rope 3. The rotation of the DC motor 7 can drive the lead screw in the lead screw module 6 to rotate, so that the movable end moves when the lead screw rotates. The linear movement of the movable end can pull and relax the rope, and cooperate with the flexible connecting piece to make the snake-shaped arm complete the corresponding action.

[0043] In the embodiment, the base 5 is provided with a pitch motor 8. The base 5 is connected with the first end joint through the output end of the pitch motor 8. The pitch motor 8 is electrically connected with the upper computer. The setting of the pitch motor 8 can help the snake-shaped arm to have more degrees of freedom, and improve the accuracy of the positioning operation.

[0044] In the embodiment, the base 5 is provided with a yaw motor 9 for controlling the turning of the base 5. The yaw motor 9 is electrically connected with the upper computer. The setting of the yaw motor 9 can help the snake-shaped arm to have more degrees of freedom, and improve the accuracy of the positioning operation.

[0045] In the embodiment, the number of the joints is 36, and the number of the ropes 3 is 4. Two ropes 3 are arranged in a group in a group of channels, and each group of ropes 3 can complete a corresponding driving action.

[0046] In use, the yaw motor 9 is used to adjust the steering of the base 5, so as to adjust the direction of the whole snake arm, facilitating the preliminary alignment of the target. The pitch motor 8 is used to control the pitch angle of the snake arm, facilitating the second alignment of the target.

[0047] According to the need, the corresponding DC motor 7 is operated to drive the moving end of the lead screw module 6 to move, so as to drive the corresponding rope 3 to move, so that the rope 3 pulls or loosens the corresponding joint to move. When the rope 3 is pulled, the rope 3 will deviate to one side with the corresponding joint, so that the flexible connecting piece between the joints on the tension path will be compressed, and the snake arm will perform a corresponding spiral bending action. When the rope is loosened, the flexible connecting piece between the joints on the path will recover the deformation, thereby helping the snake arm to recover the deformation. The rope 3 of the snake arm adopts the mode of middle position connection and end position connection, so that the snake arm can perform a corresponding bending action as a whole, and the joints between the first end joint and the middle position joint can perform independent action. Of course, this is a preferred form, and the connection position can be changed according to actual needs to complete the corresponding action requirements. Different driving states of different ropes 3 can help the whole snake arm to perform various types of actions, and have strong adaptability. At the same time, due to the structure and the flexible connecting piece, the under-actuated mode is possible. The structure of the whole snake arm is simplified, the weight is reduced, and the flexible connecting piece can complete more flexible action and achieve higher carrying capacity.

[0048] The sensors, controllers and control programs mentioned in the above description are all prior art, and will not be described here.

[0049] The above disclosed embodiments of the application are only used to help explain the application. The embodiments do not describe all the details, nor limit the application to the specific embodiments described. According to the content of the specification, many modifications and changes can be made. The specification selects and describes these embodiments in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application.

Claims

1. A flexible joint underactuated rope-driven serpentine arm, characterized in that: include: A plurality of joints connected in rotation in sequence, wherein the axis of rotation of each two adjacent joints forms a fixed angle with the rotation direction so that all the joints are spiral in shape as a whole for wrapping an object, each two adjacent joints are connected by a flexible connector, and each joint is provided with two groups of channels symmetrically distributed with respect to the rotation axis of the joint, and each group of channels is provided with a plurality of rope holes (1-2) arranged at intervals; Ropes (3) are arranged in one-to-one correspondence with all rope holes (1-2) and the number thereof is less than the number of all joint degrees of freedom; the end of each rope (3) in one group of channels is passed through the first end joint rope hole (1-2), passes through the adjacent joint rope holes (1-2) in sequence, and is then fixed to the middle joint; the end of each rope (3) in another group of channels is passed through the first end joint rope hole (1-2), passes through the adjacent joint rope holes (1-2) in sequence, and is then fixed to the end joint; A base (5) is provided with rope drive assemblies corresponding to all the ropes (3) for driving each rope (3) to move, and a head end joint is connected to the base (5); A host computer, to which all of the rope drive components are electrically connected; The flexible connector is a flexible leaf spring (2), comprising a connecting portion (2-1) and a bending portion (2-2), two connecting portions (2-1) are provided and respectively connected to the two ends of the bending portion (2-2), and each connecting portion (2-1) is connected to a joint at a corresponding position; the flexible connector is in a Z-shape as a whole.

2. The flexible joint underactuated rope-driven serpentine arm according to claim 1, characterized in that: The joint is a vertebra (1).

3. The flexible joint underactuated rope-driven serpentine arm according to claim 2, characterized in that: A data line hole (1-1) is provided on the vertebral segment (1).

4. The flexible joint underactuated rope-driven serpentine arm according to claim 1, characterized in that: The serpentine arm further comprises a visual camera (4), and the visual camera (4) is electrically connected to the upper machine.

5. The flexible joint under-actuated rope-driven serpentine arm according to claim 1, characterized in that: The rope drive assembly comprises a screw module (6) and a DC motor (7), wherein the rotating end of the DC motor (7) is connected to the rotating input end of the screw module (6), and the movable end of the screw module (6) is connected to the head end of the corresponding rope (3).

6. The flexible joint underactuated rope-driven serpentine arm according to claim 1, characterized in that: A pitch motor (8) is provided on the base (5), the base (5) is connected to the head end joint via the output end of the pitch motor (8), and the pitch motor (8) is electrically connected to the upper machine.

7. The flexible joint under-actuated rope-driven serpentine arm according to claim 1, characterized in that: A yaw motor (9) is provided on the base (5) for controlling the steering of the base (5), and the yaw motor (9) is electrically connected to the upper machine.

8. The flexible joint underactuated rope-driven serpentine arm according to claim 1, characterized in that: The number of the joints is 36, and the number of the ropes (3) is 4.

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