CN113305827B

CN113305827B - Line-driven flexible mechanical arm suitable for underwater operation

Info

Publication number: CN113305827B
Application number: CN202110683855.9A
Authority: CN
Inventors: 臧红彬; 尹强; 高源�; 袁卫锋; 周军
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology
Priority date: 2021-06-21
Filing date: 2021-06-21
Publication date: 2021-11-30
Anticipated expiration: 2041-06-21
Also published as: CN113305827A

Abstract

The invention discloses a line-driven flexible mechanical arm suitable for underwater operation, belongs to the field of flexible mechanical arms, and aims to solve the problems that the existing flexible mechanical arm is mainly designed based on land space, the research on structures capable of meeting underwater application is less, or a waterproof structure is too complex, so that the requirements of practical application are difficult to meet. The device comprises an execution unit, a supporting unit, a driving unit, a connecting assembly and a rigid assembly; the execution unit comprises a working end plate, an execution joint assembly, a fixed end plate and a universal joint, wherein the working end plate, the execution joint assembly and the fixed end plate are sequentially connected through the universal joint and form the execution unit. The utility model provides a line drive mode is adopted to the arm to carry out brand-new optimization to the structure of arm, flexible arm stable in structure after the improvement, reliable, easily control can effectively promote the load of flexible arm, has higher using value and better application prospect.

Description

Line-driven flexible mechanical arm suitable for underwater operation

Technical Field

The application relates to the field of machinery, in particular to the field of flexible mechanical arms, and specifically relates to a line-driven flexible mechanical arm suitable for underwater operation.

Background

In recent years, with the development of technology and the increase of application scenes, the demand for flexible mechanical arms is increasing. A great deal of research and improvement has been made on flexible mechanical arms.

For example, chinese patent application CN202110047548.1 discloses a serpentine arm connection structure and a serpentine arm robot, the serpentine arm connection structure comprising a gimbal and a plurality of connection ropes, wherein: the universal joint is arranged between two adjacent joint sections in the snake-shaped mechanical arm and comprises a first connecting ring and a second connecting ring, the first connecting ring is connected with one joint section, the second connecting ring is connected with the other adjacent joint section, a clamping groove is formed in the first connecting ring, a connecting rod is arranged on the second connecting ring at a position opposite to the clamping groove, one end of the connecting rod is connected with the second connecting ring, a spherical joint is arranged at the other end of the connecting rod, and the joint can be movably embedded in the clamping groove; the connecting ropes are arranged along the circumferential direction of the joint sections, and the connecting ropes are respectively connected in series along the arrangement direction of the joint sections and penetrate through the joint sections.

Chinese patent application CN202011117086.8 discloses a module combined type multi-degree-of-freedom flexible mechanical arm, which comprises a plurality of base modules which are snakelike and meandered in series, wherein each base module comprises a joint unit, a connecting rod unit and a motor unit, the joint unit is of a cubic shell structure, the motor unit is arranged in the joint unit, and the output end of the motor unit is connected with one end of the connecting rod unit so as to drive the connecting rod unit to rotate in a single degree of freedom; the other end of the connecting rod unit is fixedly connected with the next joint unit adjacent to the joint unit, and the connecting rod units of the two adjacent basic modules are arranged in an angle of 90 degrees, so that the four continuous basic modules can form a multi-freedom-degree flexible joint capable of completing the turning in any direction in space. The structure can realize multi-degree-of-freedom control, but has certain limitations: 1) each motor unit needs to be controlled independently, which relates to power supply and signal wiring of the motor units, and how to avoid winding of cables is also a big problem; 2) the loads are extremely small, which can greatly limit the applications of robotic arms.

How to improve the flexible mechanical arm to simplify the structure of the device and meet the requirements of more scenes is always the aim of scientific researchers. To this end, one of the objectives of the present application is to optimize the flexible robot arm structure.

Furthermore, current flexible mechanical arm is mainly based on land space design, and then research is less to the structure that can satisfy the underwater application, or waterproof construction is too complicated, is difficult to satisfy practical application's demand. Therefore, the second purpose of the present invention is to enable the flexible mechanical arm with the optimized structure to meet the requirements of underwater operation, and to simplify the corresponding waterproof structure as much as possible.

Disclosure of Invention

The invention aims to provide a line-driven flexible mechanical arm suitable for underwater operation. The utility model provides a line drive mode is adopted to the arm to carry out brand-new optimization to the structure of arm, flexible arm stable in structure after the improvement, reliable, easily control can effectively promote the load of flexible arm, has higher using value and better application prospect. Furthermore, this application is through the improvement to transmission structure for flexible mechanical arm needs to adopt sealed place to obtain the at utmost reduction, can satisfy the demand of underwater operation application scene.

In order to achieve the purpose, the following technical scheme is adopted in the application:

the line-driven flexible mechanical arm suitable for underwater operation comprises an execution unit, a supporting unit, a driving unit, a connecting assembly and a rigid assembly;

the execution unit comprises a working end plate, an execution joint assembly, a fixed end plate and a universal joint, wherein the working end plate, the execution joint assembly and the fixed end plate are sequentially connected through the universal joint to form the execution unit;

the number of the execution joint components is N, N is a natural number and is more than or equal to 2; each executing joint component consists of M flexible arm joints, M is a natural number and is more than or equal to 1;

two first joint bases are arranged on one side, facing the fixed end plate, of the working end plate, the first joint bases are arranged in parallel, first threaded through holes are formed in the first joint bases, and the two first threaded through holes in the working end plate are designed in a coaxial line mode;

marking one surface of the flexible arm joint as a first connecting surface, and marking one surface of the flexible arm joint parallel to the first connecting surface as a second connecting surface; two second joint bases are respectively arranged on the first connecting surface and the second connecting surface, and second threaded through holes are formed in the second joint bases;

on a single flexible arm joint, the second threaded through holes on two second joint bases on a first connecting surface are designed coaxially, the second threaded through holes on two second joint bases on a second connecting surface are designed coaxially, the projection of the axis of the second threaded through hole on the second joint base on the first connecting surface is recorded as a first projection line, the projection of the axis of the second threaded through hole on the second joint base on the second connecting surface on the first connecting surface is recorded as a second projection line, and the included angle formed by the first projection line and the second projection line is 90 degrees;

two third joint bases are arranged on one side, facing the working end plate, of the fixed end plate, the third joint bases are parallel to each other, third threaded through holes are formed in the third joint bases, and the two third threaded through holes in the fixed end plate are designed in a coaxial line mode;

the working end plate is in two-degree-of-freedom rotary connection with the adjacent flexible arm joints through the matching of a universal joint with the first joint base and the second joint base, the adjacent two flexible arm joints are in two-degree-of-freedom rotary connection through the matching of a universal joint with the second joint base, and the fixed end plate is in two-degree-of-freedom rotary connection with the adjacent flexible arm joints through the matching of a universal joint with the second joint base and the third joint base;

the supporting unit comprises a motor box body, a sealing plate, a connecting cable, a watertight plug, a first support, a second support and a base line box base, wherein the motor box body is a hollow cavity with openings at two ends, the sealing plate is respectively arranged on the openings at two ends of the motor box body, and the motor box body and the sealing plate form a driving control box;

the first support and the second support are respectively a group, the first support is connected with the drive control box, the drive control box can provide support for the first support, and the second support is connected with the drive control box, and the drive control box can provide support for the second support;

the driving unit comprises a driving motor, a driving wheel, a first driven wheel, a second driven wheel, a first driving lead screw matched with the first driven wheel, a second driving lead screw matched with the second driven wheel, linear guide rails and lead screw nuts, wherein the number of the linear guide rails and the number of the lead screw nuts are respectively 2;

the driving motor is arranged in a hollow cavity of the motor box body, the driving motor is connected with the watertight plug through a connecting cable, an output shaft of the driving motor is connected with the driving wheel, and the driving wheel can be driven to rotate by the driving motor; the motor box body is provided with a connecting wire hole matched with the watertight plug, and the watertight plug is arranged on the connecting wire hole;

the first support and the second support are respectively provided with a second guide hole, the first supports are in a group, the first supports are connected with the drive control box, the drive control box can provide support for the first supports, and the first drive screw penetrates through the first supports and can rotate relative to the first supports;

the second support is connected with the driving control box, the driving control box can provide support for the second support, and the second driving screw rod penetrates through the second support and can rotate relative to the second support;

the first driven wheel and the second driven wheel are respectively meshed with the driving wheel, the first driven wheel and the second driven wheel are symmetrically arranged on two sides of the driving wheel, and the driving wheel can drive the first driven wheel and the second driven wheel to synchronously rotate in the same direction and at the same speed;

the linear guide rail is connected with the drive control box and can keep static relative to the drive control box, the screw nuts are respectively arranged on the first drive screw and the second drive screw and can respectively move along the axial direction of the first drive screw and the axial direction of the second drive screw, the screw nuts are connected with the slide block of the linear guide rail, and the slide block of the linear guide rail can limit the screw nuts;

the screw thread turning direction on the first driving screw is opposite to that of the second driving screw, the first driven wheel is fixedly connected with the first driving screw, the second driven wheel is fixedly connected with the second driving screw, and the moving direction of a screw nut on the first driving screw is opposite to that of a screw nut on the second driving screw;

along the direction from the working end plate to the fixed end plate, the execution joint assemblies are sequentially marked as the 1 st execution joint assembly, … … th execution joint assembly and … … nth execution joint assembly; i is a natural number, i is more than 1 and i is less than or equal to N;

the working end plate is provided with 1 group of perforating assemblies, the flexible arm joint of the ith execution joint assembly is sequentially provided with i groups of perforating assemblies from inside to outside along the radial direction of the flexible arm joint, and the fixed end plate is sequentially provided with N groups of perforating assemblies from inside to outside along the radial direction of the fixed end plate;

the single group of perforation components consists of 4 threading holes, the 4 threading holes in the single group of perforation components are uniformly distributed on the same circumference, wherein 2 opposite threading holes are positioned on a first projection line and form a first oblique line hole group, and the other 2 opposite threading holes are positioned on a second projection line and form a second oblique line hole group;

on the flexible arm joint of the ith execution joint assembly, marking the perforation assemblies as a 1 st perforation assembly, a 2 nd perforation assembly, … … and an ith perforation assembly in turn along the radial direction of the flexible arm joint from inside to outside;

in the radial direction from inside to outside of the fixed end plate, the perforation assemblies are sequentially marked as a 1 st perforation assembly, an … … th perforation assembly and a … … Nth perforation assembly;

the number of the driving units and the number of the connecting assemblies are respectively 2N, and one group of driving units corresponds to one group of connecting assemblies; each group of connecting assemblies consists of 2 connecting ropes, the 2 connecting ropes in each connecting assembly are respectively and correspondingly connected with the 2 lead screw nuts in each driving unit, and the driving units can drive the connecting ropes connected with the lead screw nuts on the first driving lead screws to move towards the opposite direction relative to the connecting ropes connected with the lead screw nuts on the second driving lead screws through the first driving lead screws and the second driving lead screws in the driving units;

the 1 st execution joint component takes the working end plate as a 1 st connecting end plate, a screw nut on a first driving screw rod and a screw nut on a second driving screw rod in a group of driving units are correspondingly connected with two connecting ropes in a group of connecting components, and a group of driving units can drive the two connecting ropes in the connecting components matched with the driving units to move reversely;

one end of the base line box seat is connected with the driving control box, the driving control box can provide support for the base line box seat, the other end of the base line box seat is connected with the fixed end plate, and the base line box seat can provide support for the fixed end plate;

the two groups of connecting assemblies sequentially pass through the second guide hole, the 1 st perforation assembly on the fixed end plate and the 1 st perforation assembly on the flexible arm joint in the execution joint assembly and are correspondingly connected with the first oblique line hole group in the 1 st perforation assembly on the working end plate and the second oblique line hole group in the 1 st perforation assembly;

the ith execution joint component takes a flexible arm joint which is closest to the working end plate in the ith execution joint component as an ith connection end plate, and the two groups of connection components sequentially pass through the second guide hole, the ith perforation component on the fixed end plate and the ith perforation component on the flexible arm joint in the execution joint component and are correspondingly connected with a first oblique line hole group in the ith perforation component and a second oblique line hole group in the ith perforation component on the ith connection end plate;

the rigid components are respectively arranged between the working end plate and the adjacent flexible arm joint, between two adjacent flexible arm joints and between the fixed end plate and the adjacent flexible arm joint, and can endow rigidity to the execution unit;

the single group of rigid components consists of 4 supporting springs; 4 supporting springs in the single rigid assembly are arranged in a square shape and sleeved on the connecting rope.

The motor box body is a polygonal or circular pipe body with openings at two ends.

The motor box is the both ends open-ended rectangle body, first support, second support are two respectively, first support links to each other with the both ends opening of motor box respectively, the second support links to each other with the both ends opening of motor box respectively, first support, second support symmetry set up on the motor box.

The first support, the second support and the drive control box form a rigid support body, the rigid support body is I-shaped along the projection in the vertical direction, the first drive lead screw is connected with the first support through a bearing, the second drive lead screw is connected with the second support through a bearing, and the first drive lead screw and the second drive lead screw are arranged in parallel.

Still include the protection component, the protection component cover adopts static seal on the rigid support body and between protection component and the rigid support body.

The linear guide rails are arranged on the outer wall of the drive control box in parallel.

The support unit still includes motor fixed plate, shaft coupling, motor drive plate, motor fixed plate, shaft coupling, motor drive plate are located the cavity of motor box respectively, motor fixed plate links to each other with the motor box and the motor fixed plate can provide the support for the motor box, driving motor links to each other with the motor fixed plate and the motor fixed plate can provide the support for driving motor, driving motor's output shaft passes through the shaft coupling and links to each other with the action wheel and driving motor can drive the action wheel rotation, driving motor is connected and motor drive plate can control driving motor's rotation with the motor drive plate electricity, motor drive plate electricity is connected and is linked to each other with the watertight plug through connecting cable.

The driving motor is connected with the driving wheel through a coupler, dynamic sealing is adopted between the coupler and the sealing plate, and static sealing is adopted between the sealing plate and the motor box body.

The base line box seat is provided with a base line box seat, and the base line box seat is provided with a base line box seat;

be provided with the third guide on the base line case seat, the third guide sets up on the base line case seat, be provided with in the third guide and be the loudspeaker form opening with the one end of connecting rope matched with direction through-hole and third guide towards the second guide, the loudspeaker form opening of second guide mutually supports with the loudspeaker form opening of third guide and can reduce the wearing and tearing of connecting the rope.

The working end plate, the flexible arm joint and the fixed end plate are respectively provided with a central through hole, and the central through hole of the working end plate, the central through hole of the flexible arm joint and the central through hole of the fixed end plate are sequentially communicated to form a first working channel.

The C-shaped grabbing device comprises a grabbing unit and a control unit, wherein the grabbing unit comprises at least three rotating supports, a parallel base, a grabbing connecting rod, a C-shaped grabbing rod, a grabbing motor, a grabbing rope, a return spring and a grabbing control system, the rotating supports are uniformly distributed on a working end plate, the working end plate can provide support for the rotating supports, the C-shaped grabbing rod is C-shaped, one end of the C-shaped grabbing rod is hinged to the rotating supports, and the C-shaped grabbing rod can rotate relative to the rotating supports; one end of the grabbing connecting rod is hinged with the parallel base, the other end of the grabbing connecting rod is hinged with the middle of the C-shaped grabbing rod, and the parallel base can drive the C-shaped grabbing rod to rotate relative to the rotating support through the grabbing connecting rod;

one end of the grabbing rope is connected with the grabbing motor, the grabbing motor can fold or release the grabbing rope, the other end of the grabbing rope penetrates through the first working channel to be connected with the parallel base, and the grabbing motor can drive the C-shaped grabbing rod to rotate relative to the rotating support through the grabbing rope, the parallel base and the grabbing connecting rod in sequence so as to achieve folding or loosening operation of the C-shaped grabbing rod;

the reset spring is arranged between the working end plate and the parallel base, and the grabbing connecting rod can provide restoring force for the parallel base;

the grabbing motor is connected with the grabbing control system.

The grabbing motor and the grabbing control system are respectively arranged in the driving control box.

Still include the detection unit, the detection unit is including detecting analytic system, test probe, signal transmission line, it sets up in the drive control box to detect analytic system, it links to each other with signal transmission line to detect analytic system, signal transmission line passes first working channel and links to each other with test probe, test probe passes the work end plate and test probe is located the work end plate outside.

The detection probe is one or more of a camera, a temperature sensor, a humidity sensor, an infrared sensor and a light sensor.

The flexible arm joint is sheet-shaped and is cross-like.

A group of rigid assemblies is respectively arranged between the working end plate and the adjacent flexible arm joint, between two adjacent flexible arm joints and between the fixed end plate and the adjacent flexible arm joint;

between the working end plate and the adjacent flexible arm joint, a supporting spring in the rigid assembly is arranged on a connecting rope passing through the 1 st perforation assembly; between two adjacent flexible arm joints in the 1 st execution joint assembly, a supporting spring in the rigid assembly is arranged on a connecting rope passing through the 1 st perforation assembly; between two adjacent flexible arm joints in the ith execution joint assembly, a supporting spring in the rigid assembly is arranged on a connecting rope passing through the ith perforation assembly; between the flexible arm joint closest to the working end plate in the ith execution joint component and the flexible arm joint closest to the fixed end plate in the ith-1 execution joint component, a supporting spring in the rigid component is arranged on a connecting rope passing through the ith-1 perforation component; and a supporting spring in the rigid assembly is arranged on the connecting rope passing through the Nth perforated assembly between the fixed end plate and the adjacent flexible arm joint.

The positioning device is characterized by further comprising positioning bulges matched with the supporting springs, wherein the positioning bulges are respectively arranged on the working end plate, the flexible arm joint and the fixed end plate, and the positioning bulges are determined to be bulges so as to limit the radial movement of the supporting elasticity.

The positioning bulge is annular, and the positioning bulge and the working end plate, the positioning bulge and the flexible arm joint, and the positioning bulge and the fixed end plate are integrally formed respectively.

The connecting rope is connected with the screw nut through the rope connecting piece.

Preferably, the number of the execution joint assemblies is 3, and each execution joint assembly is composed of 7 flexible arm joints.

The perforation components are distributed at equal intervals from inside to outside along the radial direction of the flexible arm joint in sequence;

the flexible arm joint of the 1 st execution joint assembly is provided with 1 group of perforation assemblies, and the distance between a threading hole in the 1 st perforation assembly and the center of the flexible arm joint is r;

the flexible arm joint of the ith execution joint assembly is provided with i groups of perforation assemblies, the distance between the perforation assemblies is b, and the distance between the threading hole in the ith perforation assembly and the center of the flexible arm joint is r + (i-1) b.

The diameters of the flexible arm joints in the single execution joint assembly are the same, and the diameter of the flexible arm joint in the 1 st execution joint assembly, the diameter of the flexible arm joint in the … … th execution joint assembly and the diameter of the flexible arm joint in the … … Nth execution joint assembly are increased in sequence.

The diameter of the flexible arm joint in the 1 st execution joint assembly, the diameter of the flexible arm joint in the … … th execution joint assembly, and the diameter of the flexible arm joint in the … … nth execution joint assembly increase in sequence.

At present, a structure for realizing deformation by wire driving has been reported in patent documents. For example, chinese patent application CN98106723.9 discloses an improved artificial tubular muscle and its application, the improved artificial tubular muscle is made of rubber or other high molecular elastic material and fiber into tubular structure, the fiber can be distributed not only in the tube wall, but also outside the tube wall, the cavity of the tubular muscle is divided into several sections of independent cavities along the axial direction, each cavity is connected to the control valve by respective pressure-resistant pipe, and these pipes are distributed in the tubular cavity in a bending way. In this scheme, fibers are used for connection and driving, but the strength is weak and the method cannot be used in a robot arm.

In the prior art, the connecting through holes in the articular segments are generally uniformly arranged in the circumferential direction of the articular segments, such as CN202110047548.1, CN202010809885.5, CN 201910748747.8. At the beginning of the design, the inventor of the present application also adopts a design in which the connecting through holes are uniformly arranged along the circumferential direction of the joint section. After the analysis, the inventor finds that the design has the following problems: 1) the sizes of different joint sections of the mechanical arm are kept consistent, so that the size of the joint section at the working end is difficult to reduce; 2) to a certain extent, the load and power consumption of the respective drive device is increased. Therefore, how to improve the structure is a difficult problem to be solved urgently.

Regarding the driving structure, chinese patent application CN201910748747.8 discloses a super-redundant linkage flexible mechanical arm based on a closed-loop driving rope, which includes a mechanical arm group, a driving rope group and a driving part, where the driving part pulls the driving rope group, and the driving rope group pulls the mechanical arm group and makes it swing; the driving rope group comprises a first driving rope and a second driving rope, and the head end of the first driving rope and the head end of the second driving rope are respectively connected with the mechanical arm group; the tail end of the first driving rope is connected with the driving part, and the tail end of the second driving rope penetrates through the rope transfer part and is connected with the driving part; the rope turning part makes the direction in which the second driving rope pulls the arm group opposite to the direction in which the first driving rope pulls the arm group. The structure adopts a mode that the driving parts correspond to the driving rope groups one to one, the requirement on a control system is high, and the whole structure is complex.

Chinese patent application CN202020023159.6 discloses a snake-shaped mechanical arm with flexible connecting rods, in the structure, each flange is provided with four evenly-arranged through holes along the circumferential direction, the driving unit comprises two turntables and two traction ropes, the two turntables are rotatably arranged on a supporting frame, a groove is arranged on the outer circumference of each turntable, the middle parts of the two traction ropes are respectively wound in the grooves of the two turntables and fixed on the turntables, the two ends of one traction rope respectively penetrate through the upper and lower through holes on all the condyle flanges in sequence and are clamped on the last flange through a steel wire chuck, and the two ends of the other traction rope respectively penetrate through the left and right through holes on all the condyle flanges in sequence and are clamped on the last flange through the steel wire chuck; each rotary table is connected with one rotary motor respectively, the two rotary motors drive the two rotary tables respectively, and the two rotary tables control tensioning and looseness prevention of the two traction ropes respectively. In this structure, the recess that relies on the carousel cooperatees with the haulage rope, realizes the rotation of arm, and the main problem of this kind of structure lies in, and haulage rope and recess surface relative slip easily takes place, and reliability and stability remain to be improved. For this reason, a more stable and reliable driving method is required.

The application carries out brand-new improvement to the structure of flexible arm, and it has following advantage:

1) the transmission mode and the structure of the supporting unit are designed in a brand-new optimization mode, dynamic sealing is replaced by static sealing based on a smart rigid-flexible integrated system design, and the problem of deep hydrodynamic sealing is solved;

2) in the application, the working end plate, the flexible arm joint and the fixed end plate of the execution unit are designed in a hollow structure, so that the real-time consistency of the internal pressure and the external pressure in the deep water environment is realized, and the problem of compression resistance in the deep water environment is solved;

3) in the application, the working end plate, the flexible arm joint and the fixed end plate of the execution unit are designed in a hollow structure, so that a limiting and setting channel is provided for the connecting rope, a first working channel is formed through the central through hole, and the problems of wiring and interference of line driving are effectively solved;

4) the coupling phase difference of the diagonal line of the flexible arm joint is controlled, so that the number of driving motors is reduced, and the cost is reduced;

5) the flexible mechanical arm is designed without a driving motor on an execution unit, so that the beach problem that the traditional mechanical arm is large in mass and large in rotational inertia is solved;

6) in the application, the radial arrangement design of the perforation assembly, the cross-like structural design of the flexible arm joint and the reducing design of the flexible arm joint in different execution joint assemblies effectively solve the problem of load of the flexible mechanical arm, greatly reduce the weight of the flexible mechanical arm, increase the load and be beneficial to expanding the application range of the flexible mechanical arm.

Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1 is a schematic view of the general assembly of the flexible robot arm in embodiment 1.

Fig. 2 is an assembly view of the combination of the execution unit and the grasping unit in embodiment 1.

Fig. 3 is an assembly view of the drive control box in embodiment 1.

Fig. 4 is an assembly structure diagram of the first drive screw in embodiment 1.

FIG. 5 is a schematic view showing the connection of two flexible arm joints in the 3 rd execution joint assembly in example 1.

FIG. 6 is a schematic view of a flexible arm joint in the 1 st execution joint assembly of example 1.

FIG. 7 is a schematic view of a flexible arm joint in the 2 nd execution joint assembly of example 1.

FIG. 8 is a schematic view of a flexible arm joint in the 3 rd execution joint assembly of example 1.

The labels in the figure are: 1. the device comprises an execution unit, 2, a base line box base, 3, a motor box body, 4, a first support, 5, a sealing plate, 6, a C-shaped grabbing rod, 7, a grabbing connecting rod, 8, a rotating support, 9, a working end plate, 10, an execution joint assembly, 11, a fixed end plate, 12, a motor driving plate, 13, a driving motor, 14, a motor fixing plate, 15, a coupler, 16, a GREEN, 20, a connecting wire hole, 21, a first driven wheel, 22, a rope connecting piece, 23, a lead screw nut, 24, a first driving lead screw, 25, a linear guide rail, 26, a second guiding piece, 27, a second threaded through hole, 28, a positioning bulge, 29, a bolt, 30, a threading hole, 31, a second joint base, 32, a central through hole, 33 and a universal joint.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Any feature disclosed in this specification may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

Example 1

The line driving flexible mechanical arm suitable for underwater operation comprises an execution unit, a supporting unit, a driving unit, a connecting assembly and a rigid assembly.

The execution unit comprises a working end plate, an execution joint assembly, a fixed end plate and a universal joint, wherein the working end plate, the execution joint assembly and the fixed end plate are sequentially connected through the universal joint to form the execution unit. In this embodiment, the number of the execution joint assemblies is 3, and each execution joint assembly is composed of 7 flexible arm joints.

One side of the working end plate facing the fixed end plate is provided with two first joint bases which are arranged in parallel, first thread through holes are formed in the first joint bases, and the two first thread through holes on the working end plate are designed in a coaxial mode.

Marking one surface of the flexible arm joint as a first connecting surface, and marking one surface of the flexible arm joint parallel to the first connecting surface as a second connecting surface; two second joint bases are respectively arranged on the first connecting surface and the second connecting surface, and second threaded through holes are formed in the second joint bases. On a single flexible arm joint, the second threaded through holes on the two second joint bases on the first connecting surface are designed coaxially, the second threaded through holes on the two second joint bases on the second connecting surface are designed coaxially, the projection of the axis of the second threaded through hole on the second joint base on the first connecting surface is recorded as a first projection line, the projection of the axis of the second threaded through hole on the second joint base on the second connecting surface on the first connecting surface is recorded as a second projection line, and the included angle formed by the first projection line and the second projection line is 90 degrees.

One side of the fixed end plate, which faces the working end plate, is provided with two third joint bases, the third joint bases are parallel to each other, third threaded through holes are formed in the third joint bases, and the two third threaded through holes in the fixed end plate are designed in a coaxial line mode.

The working end plate is connected with the adjacent flexible arm joints in a rotating mode through the cooperation of a universal joint, the first joint base and the second joint base, the two adjacent flexible arm joints are connected in a rotating mode through the cooperation of the universal joint and the second joint base, and the fixed end plate is connected with the adjacent flexible arm joints in a rotating mode through the cooperation of the universal joint, the second joint base and the third joint base.

In this embodiment, the flexible arm joint is a sheet and the flexible arm joint is cross-like. Along the direction from the working end plate to the fixed end plate, the execution joint assemblies are sequentially recorded as the 1 st execution joint assembly, the 2 nd execution joint assembly and the 3 rd execution joint assembly. Be provided with 1 group's perforation subassembly on the work end plate, 1 group's perforation subassembly has set gradually along its radial from inside to outside on the flexible arm joint of the 1 st execution joint subassembly, 2 groups's perforation subassembly has set gradually along its radial from inside to outside on the flexible arm joint of the 2 nd execution joint subassembly, 3 groups's perforation subassembly has set gradually along its radial from inside to outside on the flexible arm joint of the 3 rd execution joint subassembly, fixed end plate has set gradually 3 groups's perforation subassembly along its radial from inside to outside.

The single group of perforation components are composed of 4 threading holes, the center of the flexible arm joint is used as the circle center, the 4 threading holes in the single group of perforation components are uniformly distributed on the same circumference, wherein 2 opposite threading holes are positioned on the first projection line and form a first oblique line hole group, and the other 2 opposite threading holes are positioned on the second projection line and form a second oblique line hole group.

On the flexible arm joint of the 3 rd execution joint assembly, the perforation assemblies are sequentially recorded as the 1 st perforation assembly, the 2 nd perforation assembly and the 3 rd perforation assembly from inside to outside along the radial direction of the flexible arm joint. Along the radial from inside to outside direction of fixed end plate, record the perforation subassembly in proper order as the 1 st perforation subassembly, the 2 nd perforation subassembly, the 3 rd perforation subassembly.

Preferably, in this embodiment, the perforation assemblies are sequentially distributed from inside to outside at equal intervals along the radial direction of the flexible arm joint; the flexible arm joint of the 1 st execution joint assembly is provided with 1 group of perforation assemblies, and the distance between a threading hole in the 1 st perforation assembly and the center of the flexible arm joint is r; the flexible arm joint of the 3 rd execution joint assembly is provided with 3 groups of perforation assemblies, the distance between the perforation assemblies is b on the flexible arm joint of the 3 rd execution joint assembly, the distance between the threading hole in the 2 nd perforation assembly and the center of the flexible arm joint is r + b, and the distance between the threading hole in the 3 rd perforation assembly and the center of the flexible arm joint is r +2 b. The diameters of the flexible arm joints in the single execution joint assembly are the same, and the diameter of the flexible arm joint in the 1 st execution joint assembly, the diameter of the flexible arm joint in the 2 nd execution joint assembly and the diameter of the flexible arm joint in the 3 rd execution joint assembly are sequentially increased.

In this embodiment, the supporting unit includes a motor box, a sealing plate, a connecting cable, a watertight plug, a first support, a second support, a base line box seat, a motor fixing plate, a coupler, and a motor driving plate, where the motor box is in a rectangular tube shape with openings at two ends, the sealing plate is respectively disposed on the openings at two ends of the motor box, and the motor box and the sealing plate constitute a driving control box.

The first support and the second support are respectively two, the first support is respectively connected with openings at two ends of the motor box body, the second support is respectively connected with openings at two ends of the motor box body, and the first support and the second support are symmetrically arranged on the motor box body. The first support, the second support and the driving control box form a rigid support body, and the projection of the rigid support body along the vertical direction is I-shaped.

The drive unit comprises a drive motor, a driving wheel, a first driven wheel, a second driven wheel, a first drive lead screw, a second drive lead screw, a linear guide rail and lead screw nuts, wherein the number of the linear guide rail and the number of the lead screw nuts are respectively 2. The first driven wheel is fixedly connected with the first driving lead screw, the first driven wheel can drive the first driving lead screw to rotate, the second driven wheel is fixedly connected with the second driving lead screw, and the second driven wheel can drive the second driving lead screw to rotate.

The driving motor, the motor fixing plate, the coupler and the motor driving plate are respectively arranged in a hollow cavity of the motor box body. In this implementation, the driving motor itself includes a motor, a reducer, and an incremental encoder. The motor fixing plate is connected with the motor box body, and the motor fixing plate can support the motor box body. The driving motor is connected with the motor fixing plate, and the motor fixing plate can provide support for the driving motor. An output shaft of the driving motor is connected with the driving wheel through a coupler, and the driving motor can drive the driving wheel to rotate. The driving motor is electrically connected with the motor driving board, and the motor driving board can control the rotation of the driving motor; the motor driving board is electrically connected with the watertight plug through a connecting cable. The motor box body is provided with a connecting wire hole matched with the watertight plug, and the watertight plug is arranged on the connecting wire hole. Dynamic seal is adopted between the coupler and the sealing plate, and static seal is adopted between the sealing plate and the motor box body.

For the requirement of underwater operation, it is necessary to design the mechanical arm for waterproof performance. In this embodiment, the arm adopts the rear-mounted drive of driving motor, for guaranteeing that driving motor, motor drive board etc. electron device are in the environmental stability operation under water, has designed the drive control case. The output shaft of the driving motor is sealed by the Glae ring, and the sealing strip is embedded in the edge part of the driving control box, so that the sealing of the motor box body is realized, and the stable output of the motor power is ensured.

The first driving lead screw is connected with the first support through a bearing and can rotate relative to the first support. The second driving screw is connected with the second support through a bearing and can rotate relative to the second support; the first driving screw rod and the second driving screw rod are arranged in parallel. By adopting the structure, the screw nut on the first driving screw is positioned between the two first supports, and the screw nut on the second driving screw is positioned between the two second supports; the first support and the second support can play a role in supporting and limiting.

The first driven wheel and the second driven wheel are respectively meshed with the driving wheel, the first driven wheel and the second driven wheel are symmetrically arranged on two sides of the driving wheel, and the driving wheel can drive the first driven wheel and the second driven wheel to synchronously rotate in the same direction and at the same speed.

The linear guide is 12, and two linear guide be a set of and parallel arrangement drive control box can provide the support for linear guide on drive control box outer wall. The linear guide rail comprises a linear slide rail and a slide block arranged on the linear slide rail. The screw nuts are respectively arranged on the first driving screw and the second driving screw, and the screw nuts can respectively move along the axial direction of the first driving screw and the axial direction of the second driving screw. Meanwhile, the screw nut is connected with the slide block of the linear guide rail, and the slide block of the linear guide rail can limit the screw nut.

In this embodiment, the screw thread turning direction on the first driving screw is opposite to the screw thread turning direction of the second driving screw, the first driven wheel is fixedly connected with the first driving screw, and the second driven wheel is fixedly connected with the second driving screw. In the structure, in a driving unit, the driving wheel drives the first driven wheel and the second driven wheel synchronously, in the same direction and at the same speed, and the screw thread on the first driving screw is opposite to the screw thread on the second driving screw, so that the movement direction of the screw nut on the first driving screw is opposite to the movement direction of the screw nut on the second driving screw, namely when the screw nut on the first driving screw moves towards one side close to the driving wheel, the screw nut on the second driving screw moves towards one side far away from the driving wheel. By adopting the structure, the control quantity of the motors can be reduced, and the cost of the flexible arm is reduced.

In this embodiment, drive unit, coupling assembling are 6 respectively, and a set of drive unit corresponds a set of coupling assembling. Every group coupling assembling comprises 2 connection ropes, and 2 connection ropes in the coupling assembling correspond with 2 screw nut in the drive unit respectively and are connected, and drive unit can drive the relative and second drive screw of the connection rope that screw nut links to each other on screw nut on the drive unit through first drive screw in it, second drive screw and drive the relative and second drive screw of screw nut on the connection rope that screw nut links to each other and move towards opposite direction.

In this embodiment, one end of the base line box seat is connected with the drive control box, and the drive control box can provide support for the base line box seat; the other end of the base line box seat is connected with the fixed end plate, and the base line box seat can provide support for the fixed end plate.

And the first support and the second support are respectively provided with a second guide hole. Preferably, the base line box seat further comprises a second guide member which is matched with the second guide hole, and the second guide hole is respectively arranged on the first support which is close to one side of the base line box seat and the second support which is close to one side of the base line box seat.

Considering that the relative motion between the connecting rope and the contact part can generate friction and abrasion with different degrees, the connecting rope has improved structure for the purpose, and the connecting rope can smoothly transit at certain corners. In this embodiment, the second guide member is disposed on the second guide hole, the second guide member is provided with a guide through hole matching with the connection rope, and one end of the guide through hole of the second guide member, which is close to the base line box base, is a trumpet-shaped opening. The base line box seat is provided with a third guide piece, and the third guide piece is arranged on the base line box seat. A guide through hole matched with the connecting rope is arranged in the third guide piece, and one end of the guide through hole of the third guide piece, which faces the second guide piece, is a horn-shaped opening. In this structure, the loudspeaker form opening of second guide and the loudspeaker form opening of third guide mutually support, can not only reduce the wearing and tearing of connecting the rope, and can avoid connecting the emergence that the rope blocked the problem, guarantee stable, the reliable operation of equipment.

The 1 st execution joint component takes the working end plate as a first connecting end plate, a screw nut on a first driving screw in a group of driving units and a screw nut on a second driving screw are correspondingly connected with two connecting ropes in a group of connecting components, and a group of driving units can drive the two connecting ropes in the connecting components matched with the driving units to move reversely. In the structure, in the driving unit matched with the first connecting end plate, the movement direction of the screw nut on the first driving screw is opposite to that of the screw nut on the second driving screw, so that one connecting rope moves to one side close to the driving wheel, the other connecting rope moves to one side far away from the driving wheel, and then the 1 st executing joint component is driven to bend towards the corresponding direction.

Because the work end plate cooperates with two sets of coupling assembling, two sets of drive unit for the end of flexible arm can be to two directions crooked. Specifically, for the first connection end plate, the two groups of connection assemblies sequentially pass through the second guide hole, the 1 st perforation assembly on the fixed end plate, and the 1 st perforation assembly on the flexible arm joint in the execution joint assembly and are correspondingly connected with the first oblique line hole group in the 1 st perforation assembly on the working end plate and the second oblique line hole group in the 1 st perforation assembly.

The 3 rd execution joint assembly takes the flexible arm joint closest to the working end plate in the 3 rd execution joint assembly as a third connecting end plate. Two sets of coupling assembling pass through second guiding hole, the 3 rd perforation subassembly on the fixed end plate in proper order, carry out the 3 rd perforation subassembly on the flexible arm joint in the joint subassembly to with the 3 rd on connecting the end plate first slash hole group in the 3 rd perforation subassembly, the corresponding connection of second slash hole group in the 3 rd perforation subassembly. The 2 nd execution joint assembly takes the flexible arm joint closest to the working end plate in the 2 nd execution joint assembly as a second connecting end plate, and the other connecting modes are similar to the 3 rd execution joint assembly.

A group of rigid assemblies are respectively arranged between the working end plate and the adjacent flexible arm joint, between two adjacent flexible arm joints and between the fixed end plate and the adjacent flexible arm joint, and the rigid assemblies can endow rigidity to the execution unit. In this embodiment, a single set of rigid components consists of 4 support springs; 4 supporting springs in the single rigid assembly are arranged in a square shape and sleeved on the connecting rope.

Preferably, between the working end plate and the adjacent flexible arm joint, a supporting spring in the rigid assembly is arranged on the connecting rope passing through the 1 st perforation assembly; between two adjacent flexible arm joints in the 1 st execution joint assembly, the supporting spring in the rigid assembly is arranged on the connecting rope passing through the 1 st perforation assembly. Between two adjacent flexible arm joints in the 3 rd execution joint assembly, a supporting spring in the rigid assembly is arranged on a connecting rope passing through the 3 rd perforation assembly; the same structure is also adopted between two adjacent flexible arm joints in the 1 st and 2 nd execution joint assemblies. Between the flexible arm joint closest to the working end plate in the 3 rd execution joint assembly and the flexible arm joint closest to the fixed end plate in the 2 nd execution joint assembly, a supporting spring in the rigid assembly is arranged on a connecting rope passing through the 2 nd perforation assembly; the same structure is also adopted between the flexible arm joint closest to the working end plate in the 2 nd execution joint assembly and the flexible arm joint closest to the fixed end plate in the 1 st execution joint assembly. And a supporting spring in the rigid assembly is arranged on a connecting rope passing through the 3 rd perforated assembly between the fixed end plate and the adjacent flexible arm joint.

Furthermore, still include with supporting spring matched with location arch, the location arch sets up respectively on work end plate, flexible arm joint, fixed end plate and just be fixed for the arch and can carry on spacingly to supporting elastic radial motion. The positioning bulge is annular, and is integrally formed with the working end plate, the flexible arm joint and the fixed end plate respectively. Further, still include the rope connecting piece, connect and link to each other through the rope connecting piece between rope and the screw nut.

In this embodiment, the working end plate, the flexible arm joint, and the fixed end plate are respectively provided with a central through hole, and the central through hole of the working end plate, the central through hole of the flexible arm joint, and the central through hole of the fixed end plate are sequentially communicated to form a first working channel.

Preferably, the device also comprises a protective assembly, wherein the protective assembly is sleeved on the rigid support body, and static seal is adopted between the protective assembly and the rigid support body.

In this embodiment, the execution unit is composed of a working end plate, three execution joint assemblies and a fixed end plate, each execution joint assembly can be bent in any direction, and the execution joint assembly is composed of a plurality of flexible arm joints, and the flexible arm joints are the most basic units for forming the execution unit. In this structure, the rigid component gives the execution unit certain rigidity, can produce the deformation under the drive of connecting rope, has good space continuity. Therefore, the inventor creates a sample on the basis of simulation.

Practical test results show that in the execution unit of the embodiment, each execution joint component can be flexibly bent under the action of the connecting rope, and the maximum bending angle is 100 degrees. Each executing joint component is connected by two groups of connecting components (namely four connecting ropes). In total, the whole mechanical arm needs 12 connecting rope drives. The total length of the line-driven continuum robot is 1545mm, wherein the length of the driving control box is 891 mm.

In this embodiment, the flexible arm joints adopt a cross hinge type joint structure, the execution unit is formed by sequentially connecting the cross hinge type joints in series, and the flexible arm joints are separated by the support spring. The supporting spring can ensure the uniformity of each flexible arm joint of the mechanical arm, fit a constant curvature bending state and improve the controllability of the mechanical arm.

The working end plate and the adjacent flexible arm joints, the two adjacent flexible arm joints and the fixed end plate and the adjacent flexible arm joints are matched through the bolts and the universal joints to form a cross hinge structure with two degrees of freedom, so that the flexible bending capability of the execution unit is realized.

As shown, the present embodiment further includes a grasping unit. The grabbing unit comprises a grabbing bottom plate, a rotating support, a parallel base, a grabbing connecting rod, a C-shaped grabbing rod, a grabbing motor, a grabbing rope, a return spring and a grabbing control system. The number of the rotating supports is four, the grabbing bottom plate is fixedly connected with the working end plate, and the rotating supports are uniformly distributed on the grabbing bottom plate.

In this embodiment, the C type is grabbed the pole and is the C type, and the C type is grabbed the one end of pole and is rotated the support and articulate, and the C type is grabbed the pole and can rotate the support relatively. One end of the grabbing connecting rod is hinged to the parallel base, the other end of the grabbing connecting rod is hinged to the middle of the C-shaped grabbing rod, and the parallel base can drive the C-shaped grabbing rod to rotate relative to the rotating support through the grabbing connecting rod. In the structure, when the four C-shaped grabbing rods approach to the center, the grabbing operation of an object can be realized; and conversely, when the four C-shaped grabbing rods are far away from the center, the loosening operation of the grabbing unit is realized.

One end of the grabbing rope is connected with a grabbing motor, and the grabbing motor can fold or unfold the grabbing rope; the other end of the grabbing rope passes through the first working channel and is connected with the parallel base. In the structure, when the grabbing motor sequentially passes through the grabbing rope, the parallel base and the grabbing connecting rod, the C-shaped grabbing rod can be driven to rotate relative to the rotating support, so that the C-shaped grabbing rod is folded or loosened.

The return spring is arranged between the working end plate and the parallel base, and the grabbing connecting rod can provide restoring force for the parallel base; the grabbing motor is connected with the grabbing control system.

In this embodiment, the grabbing motor and the grabbing control system are respectively arranged in the driving control box.

In the structure, when the grabbing motor does not work, the C-shaped grabbing rod is in an open state under the elastic force action of the return spring. When an object needs to be grabbed, the grabbing motor drives the grabbing ropes to enable the grabbing ropes to pull the parallel base tightly, and the return springs are compressed, so that the four C-shaped grabbing rods are driven to be closed to tightly grasp the object. The grabbing units are connected with the working end plate through bolts, and damaged four-claw grabs or other kinds of grabs can be replaced quickly.

In this embodiment, the grasping unit may also be replaced with a detecting unit. Specifically, the detection unit comprises a detection analysis system, a detection probe and a signal transmission line, wherein the detection analysis system is arranged in the drive control box and is connected with the signal transmission line, the signal transmission line penetrates through the first working channel and is connected with the detection probe, the detection probe penetrates through the working end plate, and the detection probe is positioned on the outer side of the working end plate. In this embodiment, the detection probe is one or more of camera, temperature sensor, humidity transducer, infrared sensor, light sensor to satisfy the needs of multiple detection.

Based on the above scheme, the flexible mechanical arm of this implementation has following advantage.

1. The flexible mechanical arm of this embodiment adopts the integrated design of rigid-flexible integration mechanical system, carries out optimal design to the resistance to pressure, leakproofness and the lightweight scheduling problem of flexible arm. The bending angle of the single-stage execution joint assembly of the flexible arm exceeds 90 degrees, and the three-stage execution joint assembly has S-shaped motion and O-shaped curling capability and has the operation capability of grabbing objects with the weight of 2kg at the depth of 100 meters under water.

2. Modeling and simulating flexible cable kinematics, and verifying the feasibility of the kinematics model through MATLAB and ADAMS simulation. And (3) planning the track by adopting a cubic curve, so that the flexible arm has excellent obstacle crossing and avoiding capability.

3. And through the multi-motor coordination control, the coupling phase difference control of the diagonal lines of the executing joint assemblies at all levels of the flexible arm is realized, the number of control motors is reduced, and the problem of high cost of the flexible arm is solved.

The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.

Claims

1. The line-driven flexible mechanical arm suitable for underwater operation is characterized by comprising an execution unit, a supporting unit, a driving unit, a connecting assembly and a rigid assembly;

2. The line driven flexible mechanical arm as claimed in claim 1, wherein the motor case is a polygonal or circular tube with two open ends.

3. The line driven flexible robot arm of claim 1, further comprising a shield assembly, wherein the shield assembly is sleeved on the rigid support body and a static seal is adopted between the shield assembly and the rigid support body.

4. The line driven flexible mechanical arm as claimed in claim 1, further comprising a second guide member fitted with a second guide hole, the second guide hole being respectively provided on the first support near one side of the base line housing and the second support near one side of the base line housing, the second guide member being provided on the second guide hole, a guide through hole fitted with the connecting rope being provided in the second guide member, and an end of the guide through hole of the second guide member near the base line housing being flared;

5. The line-driven flexible mechanical arm as claimed in claim 1, wherein the working end plate, the flexible arm joint and the fixed end plate are respectively provided with a central through hole, and the central through hole of the working end plate, the central through hole of the flexible arm joint and the central through hole of the fixed end plate are sequentially communicated to form a first working channel.

6. The line-driven flexible mechanical arm according to claim 5, further comprising a grabbing unit, wherein the grabbing unit comprises at least three rotating supports, a parallel base, a grabbing connecting rod, a C-shaped grabbing rod, a grabbing motor, a grabbing rope, a return spring and a grabbing control system, the rotating supports are uniformly distributed on the working end plate, the working end plate can provide support for the rotating supports, the C-shaped grabbing rod is C-shaped, one end of the C-shaped grabbing rod is hinged to the rotating support, and the C-shaped grabbing rod can rotate relative to the rotating support; one end of the grabbing connecting rod is hinged with the parallel base, the other end of the grabbing connecting rod is hinged with the middle of the C-shaped grabbing rod, and the parallel base can drive the C-shaped grabbing rod to rotate relative to the rotating support through the grabbing connecting rod;

the grabbing motor is connected with the grabbing control system.

7. The line driven flexible mechanical arm according to claim 5, further comprising a detection unit, wherein the detection unit comprises a detection analysis system, a detection probe and a signal transmission line, the detection analysis system is arranged in the drive control box and is connected with the signal transmission line, the signal transmission line passes through the first working channel and is connected with the detection probe, the detection probe passes through the working end plate and is positioned outside the working end plate.

8. The line driven flexible mechanical arm as claimed in claim 1, further comprising positioning protrusions cooperating with the support springs, the positioning protrusions being respectively disposed on the working end plate, the flexible arm joint, and the fixed end plate and being positioned so that the protrusions can limit radial movement of the support springs.

9. The wire-driven flexible mechanical arm as claimed in any one of claims 1 to 8, wherein the flexible arm joint is a sheet-like joint and the flexible arm joint is cross-like.

10. The line driving flexible mechanical arm according to any one of claims 1 to 9, wherein the perforation assemblies are distributed at equal intervals from inside to outside in the radial direction of the flexible arm joint;