A reconfigurable modular flexible-cable parallel robot for welding irregular workpieces

Abstract

The present invention discloses a reconfigurable modular flexible cable parallel robot for welding irregular workpieces, including a reconfigurable track unit, a plurality of support modules arranged at intervals are mounted on the reconfigurable track unit, a winding module and a mechanical arm support module are respectively installed on the support module through a sliding module, the winding module is two parallel arrangements of one above and one below, a mechanical arm module is installed on the mechanical arm support module, the mechanical arm module includes a hoisting mechanical arm module and a welding mechanical arm module, the hoisting mechanical arm module is hoisted with a cylinder hoisting module through two mechanical arm ropes, and a welding equipment module driven by two mechanical arm ropes is installed at the end of the welding equipment module. The present invention is mainly divided into a reconfigurable track, a welding module unit and a hoisting module unit, and through different combinations of the three modules, a reconfigurable modular flexible cable parallel drive operation is formed, so that the equipment can adapt to various irregular workpieces, thereby more accurately controlling the end.

Description

Technical Field

[0001] The invention relates to the field of robots, in particular to a reconfigurable modular flexible-cable parallel robot for welding irregular workpieces. Background Art

[0002] As an important representative of the development of artificial intelligence technology, robots play an important role in both industry and life. Among them, welding robots effectively improve production efficiency in engineering applications, reduce the labor intensity of workers, and have good stability. However, problems such as porosity and welding deviation will occur during the welding process, which are more prominent on large thin-plate weldments. Large thin-walled weldments are generally large in size, low in rigidity, and complex in surface shape. During the processing, they are often accompanied by factors such as wear and vibration that affect the surface quality of weldments. In order to avoid the problem of low workpiece rigidity, conventional CNC machining generally uses more conservative machining parameters to ensure surface quality, but reduces machining efficiency and is difficult to meet the requirements for lightweight and integrated structures and structural mechanical properties.

[0003] Most of the existing welding robots are articulated serial robots, the most common of which are six-axis welding robots and seven-axis welding robots. However, their working space is often limited, especially when facing large workpieces, their flexibility is greatly reduced, and it is more prominent when the object is an irregular workpiece. If you want to expand their working space, you can only increase the number of joints or lengthen the joints, which will further increase the cumulative error of the mechanism, thereby reducing the accuracy of the welding equipment module.

[0004] Due to these shortcomings of serial and parallel robots, in order to expand their applicability in industry, some existing industrial robots have adopted parallel processing methods. For example, the Chinese invention patent with application number 202111477007.9: A method for prefabrication and welding of pipe sections for modular manufacturing of chemical equipment, the mechanism adopts a parallel method as a whole, and each module is an independent serial robot arm, but because the robot arm occupies a large space area, the working space is small. When processing irregular-shaped workpieces, the traditional serial robot arm performs generally, so some invention patents add movable tracks on the basis of traditional serial robot arms. For example, the Chinese invention patent with application number 202111125300.9: A welding device suitable for valve production and manufacturing and the Chinese invention patent with application number 202210020126.X: Positioning mechanism and welding robot. The characteristics of both invention patents are that on the basis of traditional serial robot arms, circular tracks are used to cooperate with welding equipment, and the movement of welding equipment is used to enhance the flexibility of the equipment during the welding process, but due to the volume of the robot arm itself, there is still a problem of small working space and a certain cumulative error. Therefore, some invention patents have been developed that use parallel connection to complete the hoisting and welding process. For example, the invention patent with application number 201410090629.X: A modular reconfigurable flexible cable parallel mechanism experimental platform, which combines circular tracks and traditional flexible cable parallel connection to increase the working space, but uses a single-side rope hoisting mode with low rigidity, and is generally used for traditional hoisting operations, with limited applicable scenarios.

[0005] In summary, the present invention aims to increase the working space of the equipment while improving the rigidity and control accuracy of the equipment, so that its applicability is more extensive. Therefore, the present invention designs a reconfigurable modular flexible cable parallel robot for welding irregular workpieces. The overall flexible cable parallel form is adopted, which not only increases its working space, but also improves the flexibility of the equipment during the welding process. The traditional flexible cable parallel structure has the problem of low rigidity, so the robot arm module in the present invention adopts the form of rigid-flexible coupling to improve the rigidity of the system. The welding module unit is driven by two ropes, and the winding module is designed to connect the ropes on the connecting shaft according to a specific winding method, which effectively avoids interference between the driving rope and the workpiece. Changing the angle of the robot arm module can adjust the two configurations of single-sided lifting or parallel pulling. At the same time, the variable stiffness module can effectively control the tension change of the rope.

[0006] When processing irregular welded parts, the welding method adopts layer-by-layer welding, generally from bottom to top. The lifting module unit is used to fix the welded parts, the welding module unit welds the workpiece, the gear group controls the angle of the robot arm module, and the rope controls the angle of the welding gun. With the reconfigurable track, the welding gun can be freely controlled to reach the predetermined position to meet the welding needs of irregular workpieces and complex curved surfaces. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects and shortcomings of the prior art and to provide a reconfigurable modular flexible rope parallel robot for welding irregular workpieces. The overall parallel form is adopted to increase the working space of the present invention. The robotic arm module increases the stiffness of the overall structure through rigid-flexible coupling, and at the same time cooperates with the variable stiffness module to control the tension of the rope. The flexibility and efficiency of the robot are increased through a reconfigurable modular method, so that it can adapt to a variety of irregular workpieces. The winding module can avoid the interference of the rope itself and the interference between the rope and the workpiece.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A reconfigurable modular flexible cable parallel robot for welding irregular workpieces, comprising a reconfigurable track unit, a support module, a sliding module, a winding module, a mechanical arm support module, a mechanical arm module, a hoisting mechanical arm module, a welding mechanical arm module, a cylinder hoisting module, a mechanical arm rope and a welding equipment module, wherein a plurality of support modules arranged at intervals are mounted on the reconfigurable track unit, a winding module and a mechanical arm support module are respectively installed on the support module through a sliding module, the winding modules are arranged in parallel in two, one above and one below, a mechanical arm module is installed on the mechanical arm support module, the mechanical arm module comprises a hoisting mechanical arm module and a welding mechanical arm module, the hoisting mechanical arm module is hoisted with a cylinder hoisting module for installing a workpiece through two mechanical arm ropes, and a welding equipment module driven by two mechanical arm ropes is installed at the end of the welding equipment module;

[0010] The driving process of the hoisting robot arm module is as follows: a robot arm rope is first led out from the lower winding module, guided by the winding pulley group on the upper winding module, bypasses the robot arm support module, and then passes through the hoisting robot arm module, and extends from the front end of the hoisting robot arm module to be connected to the lifting ring pulley module at the upper end of the cylinder hoisting module; another robot arm rope is led out from the upper winding module, bypasses the robot arm support module, passes through the hoisting robot arm module, and then extends from the front end of the hoisting robot arm module to be connected to the lifting ring pulley module at the lower end of the cylinder hoisting module;

[0011] The driving process of the welding robot arm module: a robot arm rope is first led out from the lower winding module, guided by the winding pulley group on the upper winding module, bypassing the robot arm support module, and then passing through the lifting robot arm module in sequence, and extending from the front end of the lifting robot arm module to be connected to the lifting ring pulley module at the upper end of the cylindrical lifting module; another robot arm rope is first led out from the upper winding module, bypassing the robot arm support module, passing through the lifting robot arm module in sequence, and extending from the front end of the lifting robot arm module to be connected to the lifting ring pulley module at the lower end of the cylindrical lifting module.

[0012] The reconfigurable track unit is composed of different numbers of reconfigurable tracks. The material of the reconfigurable track is a profile. Adjacent reconfigurable tracks are connected by movable hinges and can be assembled into reconfigurable track units of different shapes according to needs. The reconfigurable track unit is a triangle, a quadrilateral, a pentagon or a hexagon. It is composed of at least three sections of profiles with equal lengths and two movable hinges. It can be folded during transportation and storage, which greatly reduces the space occupied and improves the speed of construction.

[0013] The support module includes a plurality of independently arranged support frames, each of which includes two long profiles arranged in parallel, and the two long profiles are connected by a short profile spaced apart up and down, and the two sides of the short profile are respectively connected and fixed to the inner side of the long profile by elastic fasteners. The elastic fastener connection greatly improves the portability of the installation. A threaded hole may also be provided at one end of the long profile, and a stud connection is used when installed on the reconfigurable track to enhance the stability of the present invention. The bottom end of the long profile is installed on the reconfigurable track unit through a disassembly and assembly module, and sliding modules for fixing the winding module and the robot arm support module are respectively installed on the front end surface of the long profile, and the sliding module includes a linear slide rail laid on the front end surface of the long profile, and sliding bases arranged at intervals are distributed on the linear slide rail.

[0014] The linear slide is provided with through holes with the same spacing, which are used to cooperate with the support frame to be fixed on the support frame. The T-bolt is connected with the square nut through the linear slide, so that the linear slide is fixed on the long profile of the support frame. The sliding base can slide freely on the linear slide, and is provided with four through holes around it, and a large through hole in the center. In more common operations, the T-bolt and the square nut are selected to fix the sliding module on the linear slide. The through holes around are used to fix the module connected to the sliding base. In the present invention, the wire winding module and the robot arm support module are fixed to the sliding base by the bolt connection. The number of sliding bases is added according to demand to enhance the stability of the equipment. The sliding base in the present invention is installed with the wire winding module and the robot arm support module, and a set of two sliding bases are used.

[0015] The winding module is used to provide the driving force required by the welding equipment module, including a winding base, two winding end caps arranged in parallel are installed on the winding base, a winding connecting shaft is rotatably installed between the winding end caps, a plurality of winding rings arranged at intervals are mounted on the winding connecting shaft, and the winding rings are connected and fixed by the winding ring fixing shaft, and a winding pulley group for supporting the rope is also installed on the winding base, and the rotation of the winding connecting shaft is driven by the motor on one side thereof. The starting point of the rope is wound around the winding connecting shaft in the winding module, and generally, the end does not need to be displaced to a large extent, so the rope is wound around the right end of the winding connecting shaft, and the two winding pulleys after the winding ring pass through the robot arm module, and the winding ring is connected to the winding connecting shaft by bolts. After the rope passes through the winding ring, the rope can avoid stacking during the winding process. The winding pulley is installed on the winding pulley seat to play a guiding role. Two winding modules are used on each modular device of the present invention to control two ropes respectively, and then control the welding equipment module. The winding module on the upper end of the modular device is installed with one more set of pulleys and pulley seats than the winding module on the lower end, in order to guide the ropes led out from the winding module on the lower end, and avoid interference between the ropes and the winding module and the workpiece. The position of the winding module can be adjusted as needed, and the winding module can be fixed in the corresponding position before processing. The winding module is installed on the support frame and can move with the sliding module to reduce the jitter of the rope during the force transmission process and enhance the overall stability and accuracy of the mechanism.

[0016] The robot arm support module includes a robot arm support frame base, on which a robot arm support frame connecting shaft for installing the robot arm module is mounted through a support frame, and a robot arm support frame gear set is mounted at one end of the robot arm support frame connecting shaft, and the rotation of the robot arm support frame gear set is driven by a robot arm support frame motor on one side thereof. Four through holes are arranged around the robot arm support base for cooperating with the sliding base in the sliding module, and the bolts and nuts are used to install the sliding base on the sliding base, and the robot arm support module is used to fix the robot arm module, and the through hole at one end of the robot arm module cooperates with the robot arm support base connecting shaft in the robot arm support module, and can rotate at a large angle, thereby realizing the rotation of the robot arm. The robot arm support module can control the position of the robot arm, and then control the cable exit point at the end of the robot arm.

[0017] The lifting robot arm module includes a robot arm outer frame for supporting and guiding the robot arm rope, one end of the robot arm outer frame is fixedly mounted on the robot arm support frame connecting shaft of the robot arm support module, the other end of the robot arm outer frame is fixedly mounted with a hemispherical pulley module, and a robot arm tensioning wheel and a variable stiffness module are installed in the robot arm outer frame.

[0018] The hemispherical pulley module is composed of a U-shaped hinge module and a hemispherical pulley. The U-shaped hinge module is composed of a large circular ring base, a medium circular ring base, a small circular ring base, a long connecting shaft, and a short connecting shaft. The large circular ring base and the medium circular ring base are connected by the short connecting shaft, and the medium circular ring base and the small circular ring base are connected by the long connecting shaft. The middle of the hemispherical pulley is provided with an arc-shaped guide groove, and through holes for the robot arm rope to pass through are provided on both sides of the corresponding position of the arc-shaped guide groove;

[0019] The variable stiffness module includes a variable stiffness inner connecting ring, on which a variable stiffness module ring outer frame and a variable stiffness module ring inner frame unit are mounted, an insert is provided on the inner side of the variable stiffness module ring inner frame unit, an open slot for inserting the insert is provided on the inner side of the variable stiffness module ring outer frame, four variable stiffness module ring inner frame units are evenly distributed along the circumference of the variable stiffness inner connecting ring, and grooves are provided between the variable stiffness module ring inner frame units to adapt to the tension of the robot arm rope, and the outer side of the variable stiffness module ring inner frame unit is connected to the variable stiffness module ring outer frame by a spring. When the robot arm rope is pulled, the ring inner frame unit is squeezed and moves inward along the diameter direction, and when the rope tension is reduced, the ring inner frame unit returns to its original state under the tension of the spring. The connecting ring is connected to the robot arm connecting shaft of the robot arm module.

[0020] The cylindrical hoisting module includes a cylindrical frame, and grooves arranged at intervals are uniformly distributed in the outer circumferential direction of the cylindrical frame. A sliding track is installed in the groove, and a through hole for installing the sliding track is provided inside the groove. A ring pulley module for connecting the rope of the robot arm is installed on the sliding track, and the ring pulley module forms a parallel pulling form for two pairs. The ring pulley module consists of a ring base, a ring connecting shaft and a ring pulley. The upper end of the cylindrical frame is installed with an end connecting frame for installing the workpiece. The cylindrical frame is designed to be cylindrical in order to adapt to the characteristics of reconfigurable modularization. When the reconfigurable track and the module unit cooperate to form a form between three and six ropes, the cylindrical frame can be installed with multiple sliding tracks and the ring modules in accordance with the number of ropes. The sliding track is used to connect the cylindrical frame and the ring module. The sliding track is provided with multiple through holes for fixing the sliding track on the cylindrical frame and fixing the ring module. A rectangular groove is provided on one side of the sliding track for positioning the ring module, which is convenient for installation. The lifting ring module is composed of the lifting ring base, the lifting ring connecting shaft and the lifting ring pulley. A rectangular platform is provided at the bottom of the lifting ring base, which is used to cooperate with the groove on the front of the sliding track to fix the lifting ring base. The lifting ring pulley is used to connect the rope of the robotic arm. The number of the lifting ring modules is set according to the parallel form. For general lifting and grabbing work, different numbers of the sliding tracks are generally installed according to the number of ropes, and one lifting ring module is installed on each sliding track; for working conditions that require higher precision and faster speed, different numbers of the sliding tracks are installed, and two lifting ring modules are installed on each sliding track to form a parallel pulling form. The connection points of the cylindrical lifting module are set on the circumferential surface and the upper and lower surfaces, and the positions of the connection points can be changed according to needs.

[0021] The welding robot arm module includes two hingedly connected robot arm outer frames supporting and guiding robot arm ropes, and a robot arm tensioning wheel and a variable stiffness module are respectively installed in the robot arm outer frames. The bottom end of one robot arm outer frame is fixedly installed on the robot arm support frame connecting shaft of the robot arm support module, and the upper end of the other robot arm outer frame is installed with a robot arm connecting shaft. A welding equipment module is installed on the robot arm mounting shaft, and the welding equipment module includes a welding equipment module base and a welding equipment module welding gun; the welding equipment module is installed on the robot arm, and is driven by the rope to achieve a large load ratio and high dexterity, so that it can process workpieces of various irregular shapes and complex surfaces.

[0022] The method for using a reconfigurable modular flexible cable parallel robot for welding irregular workpieces is characterized by the following specific steps:

[0023] (1) System initialization: First, determine the position parameters of the workpiece to be welded, place the workpiece to be welded at a fixed position, adjust the parameters of each module, and input them into the control system host computer;

[0024] (2) The host computer determines the position of the main area of ​​the workspace according to the position parameters of the workpiece, starts the servo motor in the winding mechanism, adjusts the rope according to the position of the mechanism to balance the tension, and each sliding module, robotic arm, robotic arm support module, spring, and welding equipment module are in a stable position;

[0025] (3) During the movement of the welding equipment module, the tension sensor, angle sensor, etc. collect data and output it to the host computer, so as to control the balance mechanism to adjust with the end movement and adapt to the stiffness of the spring to meet the overall stability and accuracy of the mechanism;

[0026] (4) When performing welding tasks, the lifting module unit is used to fix the welded parts. The cylindrical lifting module at the end adjusts the position of the lifting point according to the welded parts, and cooperates with the reconfigurable track to meet the needs of supporting welded parts with different shapes and complex curved surfaces, thereby reducing the stiffness changes of the welded workpieces.

[0027] (5) The welding equipment module controls the robot arm module and the welding gun through two ropes with a total of three degrees of freedom. The ropes pass through the winding module, the robot arm module, and then are connected to the end welding gun equipment module. The overall welding is carried out from bottom to top layer by layer. The gear set controls the angle of the robot arm module, and the rope controls the angle of the welding gun. Combined with the reconfigurable track, the welding gun can be freely controlled to reach the predetermined position. After setting the trajectory, irregular workpieces can be welded;

[0028] (6) When performing general lifting operations, a parallel structure is adopted, and the cable exit point is located in the middle and upper part of the overall mechanism. Different shapes of reconfigurable tracks are matched, and different numbers of sub-modules are installed to form different forms of lifting structures such as three cables, four cables, five cables, and six cables;

[0029] (7) When performing operations with high precision and high speed, the parallel structure is still used. Some submodules adjust the cable point position to the middle and lower part of the overall mechanism, and the other part remains in the middle and upper part of the overall mechanism. They cooperate with each other to form a pulling structure, thereby improving the speed of the overall mechanism operation.

[0030] (8) After ensuring that the welded parts are completely covered, the welding operation is completed and the system is initialized.

[0031] The principle is as follows: the present invention applies the flexible cable drive structure to the field of welding of irregular workpieces, realizes the rigid-flexible coupling structure through modularization, and quickly performs the welding process while ensuring stability. The reconfigurable track can improve the flexibility of module movement compared to general tracks. Reconfigurable modularization can improve the overall working space. Since the early winding part was installed at the bottom and the end effector was controlled by the pulley, when the end effector moved to a position close to the pulley, the horizontal force was too small and the end could not be well controlled. However, the winding part was installed on the slider of the support frame, and the horizontal force of the end effector could be adjusted by adjusting the position of the slider to make it more reasonable, thereby achieving accurate control of the end effector. The use of the robotic arm module and the variable stiffness module can effectively control the telescopic tension while increasing flexibility.

[0032] Through the reconfigurable track and the assembly of the hoisting modular unit, the use scenarios of the mechanism are increased. In general hoisting operations, the traditional soft rope drive hoisting operation is adopted. The number of ropes is determined according to the needs. The reconfigurable track and the support module cooperate to form a multi-rope drive; the angle of the manipulator is adjusted during precise and fast operations, and a pulling structure is formed by using multiple support modules and reconfigurable tracks. When performing welding tasks, the welding module unit is added, and the reconfigurable track and hoisting module unit are used to control the position and posture of the end effector in real time, which not only increases the working space of the equipment, but also improves the accuracy and efficiency of the operation. At the same time, the robot arm module and the variable stiffness module are used to improve the dexterity of the equipment while adjusting the tension of the rope in real time, so that the equipment can adapt to various irregular workpieces, thereby performing more accurate control of the end.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The present invention is mainly divided into a reconfigurable track, a welding module unit and a hoisting module unit. Through different combinations of the three modules, a reconfigurable modular soft cable parallel drive operation is formed, so that the end can adapt to a variety of irregular workpieces and increase the working space. A hemispherical pulley module is installed at the end of the hoisting module unit. After the rope passes through the device, the angle change can be effectively adjusted according to the movement of the end, reducing the error caused by rope vibration. The end of the welding module unit can also replace the end effector according to different scenarios.

[0035] 2. The robot arm module adopts a rigid-flexible coupling structure, which increases the rigidity of the system, and uses rope drive to improve the flexibility of the system. For general operations, the robot arm angle can be adjusted to form a single-side lifting mode; for more complex welding processes, the lifting module unit adjusts the robot arm angle to form a pulling method to quickly and effectively control the end position, and cooperate with the welding equipment to complete the welding operation.

[0036] 3. The variable stiffness module can adjust the tension of the rope in real time to adapt to the position change of the end effector. When the rope tension increases, the spring of the variable stiffness module stretches and the inner connecting ring moves along the diameter direction. When the rope tension decreases, the spring and the inner connecting ring return to their initial state, greatly improving the accuracy and adaptability of the equipment.

[0037] 4. Design of winding module The winding ring device fixes the elongation or shortening path of the rope, and walks through the predetermined track during the winding process, reducing the impact of rope stacking on the tension of the rope and the change of the terminal posture. The cylindrical lifting module at the end can be matched with different parallel forms, and different numbers of linear slides and ring modules can be installed. Tracks and ring modules are provided on the circumferential surface and the upper and lower surfaces. Different connection points can be selected for debugging to realize the reconfigurable function of the terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of a reconfigurable modular flexible cable parallel robot for welding irregular workpieces is invented;

[0039] FIG2( a ) is a schematic diagram of a reconfigurable track-triangle of the invention;

[0040] FIG2( b ) is a schematic diagram of the reconfigurable track-quadrilateral of the invention;

[0041] FIG2( c ) is a schematic diagram of the reconfigurable track-pentagon of the invention;

[0042] FIG2( d ) is a schematic diagram of a reconfigurable track-hexagon of the invention;

[0043] Figure 3 It is a schematic diagram of the invention hoisting module unit;

[0044] Figure 4 A schematic diagram of the supporting framework of the invention;

[0045] Figure 5 A schematic diagram of the invented winding module;

[0046] Figure 6 A schematic diagram of a wire winding ring in the wire winding module of the present invention;

[0047] Figure 6a for Figure 6 A magnified view of the local structure;

[0048] Figure 7 This is a schematic diagram of the invented robotic arm support module;

[0049] Figure 8 A schematic diagram of the invented lifting robot arm module;

[0050] Fig. 9 Schematic diagram of the invented hemispherical pulley module;

[0051] Fig.10 It is a schematic diagram of the variable stiffness module of the invention;

[0052] Fig.11 It is a schematic diagram of the cylinder lifting module of the invention;

[0053] Fig.11a It is a structural schematic diagram of the ring pulley module;

[0054] Fig.12 Schematic diagram of welding module unit for invention;

[0055] Fig.13 This is a schematic diagram of the welding robot arm module in the welding module unit of the invention.

[0056] Fig.14 Flow chart of the welding process of the present invention.

[0057] Reference numerals:

[0058] Figure 1 : Reconfigurable track-1, disassembly module-2, support module-3, winding module-4, robotic arm support module-5, robotic arm module-6, variable stiffness module-7, welding equipment module-8, cylinder lifting module-9;

[0059] Figure 2 (a)-(d): movable hinge-12, profile-11;

[0060] Figure 3 : Support module-3, winding module-4, robotic arm support module-5, robotic arm module-6, variable stiffness module-7;

[0061] Figure 4 : Elastic fastener-31, linear slide-32, sliding base-33, short profile-34, long profile-35;

[0062] Figure 5 : Wire winding base-41, wire winding end cover-42, wire winding pulley block-43, wire winding motor-44, wire winding synchronous belt-45, wire winding ring-46, wire winding ring fixing shaft-47, wire winding connecting shaft-48;

[0063] Figure 6 : Wire wrap ring-46, ear hole-49;

[0064] Figure 7 : Robotic arm support frame base-51, robot arm support frame gear set-52, robot arm support frame connecting shaft-53, robot arm support frame motor-54;

[0065] Figure 8 : Robot arm outer frame-61, robot arm tensioning wheel-62, hemispherical pulley module-63, robot arm rope-64, variable stiffness module-7;

[0066] Fig. 9 : Large ring base-631, medium ring base-632, small ring base-633, long connecting shaft-634, short connecting shaft-635; lifting ring base-931, lifting ring connecting shaft-932, lifting ring connecting pulley 933;

[0067] Fig.10 : variable stiffness module circular ring outer frame-71, variable stiffness module circular ring inner frame unit-72, spring-73, variable stiffness inner connecting circular ring-74;

[0068] Fig.11 : Cylindrical frame-91, sliding track-92, lifting ring pulley module-93, end connecting frame-94;

[0069] Fig.12 : Support module-3, winding module-4, robotic arm support module-5, robotic arm module-6, variable stiffness module-7, welding equipment module-8;

[0070] Fig.13 :Robot arm outer frame-61, robot arm tensioning wheel-62, robot arm rope-64, variable stiffness module-7, robot arm connection DETAILED DESCRIPTION

[0071] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0072] like Figure 1 As shown, the reconfigurable modular flexible cable parallel robot for welding irregular workpieces of the present invention mainly includes a reconfigurable track-1, a disassembly module-2, a support module-3, a winding module-4, a mechanical arm support module-5, a mechanical arm module-6, a variable stiffness module-7, a welding equipment module-8, and a cylinder hoisting module-9, wherein:

[0073] As shown in Figure 2 (a)-(d), the reconfigurable track 1 is composed of an aluminum profile 11 and a movable hinge 12. Each small unit is composed of 3 sections of aluminum profiles 11 and two movable hinges 12, which can be rotated arbitrarily. Units of different numbers and angles are combined to form tracks of various shapes, such as triangles, quadrilaterals, pentagons and hexagons. Before installation, they are assembled into different shapes according to needs. As shown in Figure 2 (a)-(d) respectively. The disassembly module consists of profile angle connectors and T-bolts and nuts. During operation, the disassembly module is used to connect the reconfigurable track to the support frame. Selecting the disassembly module can realize the rapid installation and disassembly between the reconfigurable track and the support frame, and the high rigidity can make the overall structure relatively stable.

[0074] like Figure 3 As shown, the support module 3, the winding module 4, the robot support module 5, the robot module 6, the variable stiffness module 7, etc. constitute the hoisting module unit. As a kind of modular equipment, the hoisting module unit is used for general hoisting or grasping tasks. The winding module 4 is installed on the sliding base of the support module 3. Generally, the position of the winding module 4 is adjusted before processing, and then fixed with bolts; or when real-time control is required, the winding module can be chosen not to be fixed, but to follow the change of the end posture to increase the overall flexibility of the equipment. The robot support module 5 is also installed on the sliding base of the support module 3 and connected by bolts. The robot module 6 is connected to the robot support module 5. A pair of gears are provided on the robot support module 5. The gears are driven by the motor to rotate, and then the robot module 6 is driven to rotate a certain angle. The angles are freely combined according to the parallel form. In general lifting and grasping tasks, the robot arm module 6 is generally adjusted to be vertical to the ground or diagonally upward at a certain angle, and multiple lifting module units cooperate to form a traditional parallel form with a larger working space; under conditions where stable and fast working conditions are required, the robot arm module 6 can be adjusted to be diagonally downward at a certain angle, and multiple lifting module units cooperate to form a pulling form to increase the stability of the overall mechanism. Multiple lifting module units drive the ropes to enable the end to complete the changes in the degrees of freedom of translation and rotation.

[0075] like Figure 4As shown, the support module 3 is composed of different numbers of short profiles 34 and long profiles 35, elastic fasteners 31, linear slide rails 32 and sliding bases 33. The two longer long profiles 35 in the support frame are used as the main body, and three shorter short profiles 34 are used in the middle to connect the two longer profiles. The support frame is installed on the reconfigurable track 1 through the disassembly module, and the two longer long profiles 35 are installed with sliding modules. The sliding modules can slide up and down as needed and are fixed by bolts. The sliding module is composed of linear slide rails 32 and sliding bases 33. The linear slide rails 32 in the sliding module are fixed to the support module 3 by bolts, and the sliding base 33 is connected to the linear slide rails 32 and can slide up and down along the linear slide rails 32. There are four round holes on both sides of the sliding base 33, which are used to cooperate with the bottom plates in the winding module 4 and the robot support module 5, so that the winding module 4 and the robot support module 5 are fixed on the sliding base 33.

[0076] The reconfigurable track is equipped with a disassembly module for connecting the support frame so that the robot can be fixed on the ground as a whole, and the equipment can be quickly installed. A sliding module can also be installed as needed so that the support frame can slide along the reconfigurable track. The sliding module can be used when the overall rigidity requirement is not high and the precision requirement is high. The present invention is based on welding equipment, so the disassembly module is selected as the fixing device of the present invention, which can achieve the purpose of rapid disassembly while also improving the overall stability of the equipment.

[0077] The disassembly module is used to connect the support frame and the reconfigurable track. The disassembly module consists of an angle connector, a T-bolt and a square nut. The reconfigurable track is installed vertically to the support frame and fixed at one end of the support frame with a disassembly module. The angle connector is provided with two through holes. During installation, the square nut is introduced from the inside of the profile, and the T-bolt cooperates with the square nut through the through holes of the angle connector. The disassembly modules are symmetrically distributed and are located at one end of the two sections of the support frame. The reconfigurable track can be assembled into different shapes, but they are all profiles, so the same disassembly module can be fixed on the reconfigurable track and connected to the support frame.

[0078] The above-mentioned support frame is used to provide support for the sliding module and the robot support module. From the analysis of the two separate vertical and horizontal directions, in the vertical direction, since the winding module is installed on the slider of the support frame, the vertical movement is divided into two forms, one is a fixed slider, and the movement of the end effector is achieved by controlling the rope; the other is a fixed rope, and the movement of the end effector is achieved by lifting the slider. Thus, the concept of coarse adjustment and fine adjustment is introduced. In the engineering practice of thin plate welding, the end effector is firstly raised and lowered to reach the specified position by lifting the slider to achieve the purpose of coarse adjustment; then the rope is controlled to achieve the change of the end effector posture to achieve the purpose of fine adjustment, thereby realizing a step-by-step welding process, which can improve the accuracy and efficiency of the welding process. In the horizontal direction, it is possible to choose to apply active force or passive force, which is determined according to the actual situation. However, the force can always be decomposed in the horizontal and vertical directions, so that the resultant force in the vertical direction offsets the gravity, and the resultant force of the rope in the horizontal direction can control the motion state of the end effector according to the force applied, uniform or non-uniform.

[0079] The sliding module is used to cooperate with the support frame and play a supporting role at the same time. The sliding module consists of a linear slide and a sliding base. The linear slide is provided with through holes with the same spacing, which are used to cooperate with the support frame and be fixed on the support frame. T-bolts are connected through the linear slide and the square nut to fix the linear slide on the long profile of the support frame. The sliding base can slide freely on the linear slide, and is provided with four through holes around it, and a large through hole in the center. In more common operations, T-bolts and square nuts are selected to fix the sliding module on the linear slide. The through holes around are used to fix the module connected to the sliding base. In the present invention, the wire winding module and the robot arm support module are fixed to the sliding base by bolt connection. The number of sliding bases is added according to demand to enhance the stability of the equipment. In the present invention, the wire winding module and the robot arm support module are installed on the sliding base, and a set of two sliding bases are used.

[0080] like Figure 5 , 6As shown, the winding module 4 is composed of a winding base 41, a winding end cover 42, a winding pulley group 43, a winding motor 44, a winding synchronous belt 45, a winding ring 46, a winding ring fixed shaft 47, and a winding connecting shaft 48. The winding end cover 42 is fixed on the winding base 41, and the winding connecting shaft 48 is fixed on the winding end cover 42 through the winding bearing 47, which can rotate 360 ​​degrees by itself to achieve a large angle of rotation. After the rope passes through the winding ring 46, it can avoid the rope from stacking on the winding connecting shaft 48. Four winding ring fixed shafts are set, which are respectively connected to each winding ring and fixed in the through hole of the winding end cover 42; the inner circumferential direction of the winding ring is evenly distributed with ear holes for passing the rope. When winding the rope, the rope is firstly wound around the right end of the middle shaft, and then passes through the ear holes of the left winding ring in clockwise or counterclockwise order to pass the rope out, limiting the winding direction of the rope. The winding motor 44 is fixed on the winding base 41, and is connected to the winding connecting shaft 48 through the winding synchronous belt 45, so as to finally realize the synchronous movement of the winding motor 48 and the winding connecting shaft 48. The inside of the winding ring 46 and the outside of the winding connecting shaft are both provided with through holes, which are connected by bolts during installation. Four round holes are provided on both sides of the winding base 41, which are connected and fixed with the linear slide rail 32 in the sliding module by bolts. The winding pulley block is installed on the winding end cover 42, which is used to support the rope and play a guiding role to avoid interference between the ropes led out of the winding module 4 at the lower end and the upper end.

[0081] like Figure 7 As shown, the robot support module 5 is composed of a robot support frame base 51, a robot support frame gear set 52, a robot support frame connecting shaft 53, and a robot support frame motor 54. The robot support frame connecting shaft 53 is fixed to the robot support frame base 51 through a bearing, one of the gear sets is installed on the robot support frame connecting shaft 53, and the other is installed on the robot support frame motor 54. The robot support frame motor 54 is fixed to the robot support frame base 51, and the gear set cooperates to realize a rotational degree of freedom of the robot. Four round holes are provided on both sides of the robot support frame base 51, which are fixed to the sliding base 33 in the sliding module by bolts.

[0082] like Figure 8 As shown, the robot module 6 is composed of a robot outer frame 61, a robot tensioning wheel 62, a robot connecting shaft, a robot rope 64, and a variable stiffness module 65. The robot outer frame 61 in the robot module 6 is connected to the robot connecting shaft in the robot support module 6 through a bearing, and a cut-off process is performed at the top for installing a hemispherical pulley module 63. A robot tensioning wheel 62 is installed on the robot connecting shaft, and the robot rope 64 and the variable stiffness module 7 can rotate around the robot connecting shaft. The robot connecting shaft 63 is provided with four, respectively as shown in FIG. Figure 8The robot arm rope 64 is wound around the robot arm connecting shaft in a specific winding manner, and the middle robot arm connecting shaft is installed with a variable stiffness module 7. The robot arm rope 64 is connected to the end effector through the robot arm connecting shaft and the variable stiffness module 7, and the tension of the robot arm rope 64 can be adaptively adjusted to meet the needs of the operation, thereby achieving stable and efficient operation.

[0083] like Fig. 9 As shown, the hemispherical pulley module 63 is composed of a U-shaped hinge module 631 and a hemispherical pulley 632, and the U-shaped hinge module is composed of a large circular ring base 6311, a medium circular ring base 6312, a small circular ring base 6313, a long connecting shaft 6314, and a short connecting shaft 6315. The large circular ring base 6311 and the medium circular ring base 6312 are connected by a short connecting shaft 6315, and two short connecting shafts 6315 are installed in the diameter direction, and the medium circular ring base 6312 and the small circular ring base 6313 are connected by a long connecting shaft 6314. Through holes are provided on both sides of the middle of the hemispherical pulley 632, and the top of the through hole is cut and rounded. The robot arm rope 64 passes through the through hole and is wound around the cut circular surface. The hemispherical pulley 632 is fixedly connected to the U-shaped hinge module 631, and the large circular ring base 6311 is fixedly connected to the outer frame 61 of the robotic arm, so that the hemispherical pulley module 63 can rotate to a certain angle, and the hemispherical pulley 632 can guide the robotic arm rope 64 during the extension and shortening of the rope.

[0084] The above-mentioned mechanical arm module is installed on the sliding module, and forms a gear match with the sliding base in the sliding module, so that the position of the cable outlet point can be adjusted arbitrarily. In general hoisting operations, the mechanical arm module is placed vertically or tilted upward at a certain angle, and multiple modular devices are used to work together to form a classic parallel form, which greatly increases the working space of the equipment; in an environment that requires high precision and stability, the mechanical arm module can be adjusted to tilt downward and tilt upward at a certain angle, and distributed symmetrically, so as to form a pulling form, which greatly improves the control accuracy. There are four mechanical arm tensioning wheels, and three mechanical arm tensioning wheels are arranged in the middle of the mechanical arm outer frame. The rope passes through the mechanical arm tensioning wheel in an eight-shaped winding manner, which can effectively improve the stability of the rope tension. A variable stiffness module is installed on the tensioning wheel at the center position. The rope can adaptively adjust the rope tension through the variable stiffness module. Under the joint action of the mechanical arm tensioning wheel and the variable stiffness module, the error of the rope tension can be controlled within a reasonable range. The tensioning wheel at the end is used to transmit the rope tension.

[0085] like Fig.10As shown, the variable stiffness module 7 is composed of a variable stiffness module ring outer frame 71, a variable stiffness module ring inner frame unit 72, a spring 73, and a variable stiffness inner connecting ring 74. The variable stiffness module ring outer frame 71 and the inner side of the variable stiffness module ring inner frame unit 72 are installed on the variable stiffness inner connecting ring 74. The variable stiffness module ring inner frame unit 72 is connected to the variable stiffness module ring outer frame 71 through the variable stiffness inner connecting ring 74. The variable stiffness module ring inner frame unit 72 is provided with 4 grooves to adapt to the tension of the robot arm rope 64 and play a guiding role. When the robot arm rope 64 is pulled, the variable stiffness module ring inner frame unit 72 is squeezed and moves inward along the diameter direction. When the tension of the robot arm rope 64 is reduced, the variable stiffness module ring inner frame unit 72 returns to its original state under the tension of the spring. The variable stiffness inner connecting ring 74 is connected to the robot arm connecting shaft of the robot arm module 6.

[0086] like Fig.11 As shown, the cylindrical hoisting module 9 is composed of a cylindrical frame 91, a sliding track 92, and a ring pulley module 93. The cylindrical frame is used to provide support for the sliding track 92 and the ring module 93. The cylindrical frame 91 is provided with grooves around it, and through holes are provided inside the grooves for fixing the sliding track 92. The cylindrical frame 91 is designed to be cylindrical in order to adapt to the characteristics of reconfigurable modularization. When the reconfigurable track and the module unit cooperate to form a form between three and six ropes, the cylindrical frame 91 can be installed with multiple sliding tracks 92 and ring modules 93 according to the number of ropes. The sliding track 92 is used to connect the cylindrical frame 92 and the ring module 93. The sliding track 92 is provided with multiple through holes for fixing the sliding track 92 on the cylindrical frame 91 and fixing the ring module 93. A rectangular groove is provided on one side of the sliding track 92 for positioning the ring module 93, which is convenient for installation. The ring pulley module 93 is composed of a ring base 931, a ring connecting shaft 932, and a ring pulley 933. A rectangular platform is provided at the bottom of the lifting ring base 931, which is used to match the groove on the front of the sliding track 92 to fix the lifting ring base 931. The lifting ring pulley 833 is used to connect the robot arm rope 64. The number of lifting ring modules 93 is set according to the parallel form. For general lifting and grabbing work, different numbers of sliding tracks 92 are generally installed according to the number of ropes, and one lifting ring module 93 is installed on each sliding track 92; for working conditions that require higher precision and faster speed, different numbers of sliding tracks 92 are installed, and two lifting ring modules 93 are installed on each sliding track 92 to form a parallel pulling form.

[0087] like Fig.12 , 13As shown, the welding module unit is composed of a support module 3, a winding module 4, a robot support module 5, a robot module 6, a variable stiffness module 7, and a welding equipment module 8. The welding equipment module is installed on the robot arm and driven by a rope. It can achieve a large load ratio and high dexterity, enabling it to process a variety of irregular shapes and complex curved workpieces. The welding module is generally used in collaborative welding operations and is used in conjunction with the hoisting module unit and the reconfigurable track 1. The winding module 4 is installed on the sliding base of the support module 3. Generally, the position of the winding module 4 is adjusted before processing, and then fixed with bolts; or when real-time control is required, the winding module 4 can be selected not to be fixed, but to follow the change of the end posture to increase the overall flexibility of the equipment. The robot support module 5 is also installed on the sliding base of the support module 3 and is connected by bolts.

[0088] The robot arm module 6 is connected to the robot arm support module 5. The robot arm support module 5 is provided with a pair of gears. The gears are driven to rotate by the motor, and then the robot arm module 6 is driven to rotate a certain angle. The angles are freely combined according to the parallel form. When performing welding tasks, the robot arm module 6 can be adjusted to be tilted downward at a certain angle. Multiple hoisting module units cooperate to form a pulling form, which increases the stability of the overall mechanism. Under the action of the robot arm rope 64, the end completes the degree of freedom of translation and rotation. On this basis, a welding module unit is added to complete the collaborative operation. The difference between the welding robot arm module and the hoisting robot arm module is the top. The top of the welding robot arm module is the robot arm connecting shaft 66, and the top of the hoisting robot arm module is the hemispherical pulley module 63. The welding equipment module controls the robot arm module and the welding gun with a total of three degrees of freedom of rotation through two ropes. The rope passes through the winding module 4, the robot arm module 6, and is connected to the end welding gun equipment module 8. The overall welding is layered from bottom to top. The gear set controls the angle of the robot arm module 6, and the rope controls the angle of the welding gun 8. In combination with the reconfigurable track 1, the welding gun 8 can be freely controlled to reach a predetermined position. After setting the trajectory, irregular workpieces can be welded. The end effector 8 consists of an end effector base 81 and an end effector welding gun 82. The end effector base 81 is used to install the end effector welding gun 82. The end effector base 81 is connected by two robot arm ropes 64, and the posture change of the end effector welding gun 82 is realized under the action of different tensions of the robot arm ropes 64.

[0089] Depend on Fig.14 It can be seen that the welding steps of the reconfigurable modular flexible cable parallel robot for welding irregular workpieces of the present invention are as follows:

[0090] (1) System initialization: first determine the position parameters of the workpiece to be welded, place the workpiece to be welded at a fixed position, adjust the shape of the reconfigurable track 1 and the parameters of the robot arm support module 5, the winding module 4, and the cylinder lifting module 8, and input them into the control system host computer;

[0091] (2) The host computer determines the position of the main area of ​​the workspace according to the position parameters of the workpiece, the servo motor in the winding mechanism 4 is started, and the rope is adjusted according to the position shape of the mechanism to balance the tension, and each sliding base 33, the robot module 6, the robot support module 5, the spring 73, and the end effector 9 are in a stable position;

[0092] (3) During the movement of the end effector 8, the tension sensor, the angle sensor, etc. collect data and output it to the host computer, so as to control the balancing mechanism to adjust with the end movement and adapt to the stiffness of the spring 74 to meet the stability and accuracy of the mechanism as a whole;

[0093] (4) When performing welding tasks, the lifting module unit is used to fix the welded parts. The cylindrical lifting module 9 at the end adjusts the position of the lifting point according to the welded parts, and cooperates with the reconfigurable track 1 to meet the needs of supporting welded parts with different shapes and complex curved surfaces, thereby reducing the stiffness changes of the welded workpiece.

[0094] (5) The welding equipment module controls the robot arm module and the welding gun with a total of three degrees of freedom of rotation through two ropes. The ropes pass through the winding module 4, the robot arm module 6, and are connected to the end welding gun equipment module 8. The overall welding is carried out from bottom to top layer by layer. The gear set controls the angle of the robot arm module 6, and the rope controls the angle of the welding gun 8. Combined with the reconfigurable track 1, the welding gun 8 can be freely controlled to reach the predetermined position. After setting the trajectory, irregular workpieces can be welded.

[0095] (6) During general lifting operations, a parallel structure is adopted, and the cable exit point is located in the middle and upper part of the overall mechanism. Different shapes of the reconfigurable track 1 are matched, and different numbers of sub-modules are installed to form different forms of lifting structures such as three cables, four cables, five cables, and six cables.

[0096] (7) When performing operations with high precision and speed, the parallel structure is still used. One part of the lifting module units adjusts the cable outlet position to the middle and lower part of the overall mechanism, and the other part remains in the middle and upper part of the overall mechanism. They cooperate with each other to form a pulling structure, thereby improving the speed of the overall mechanism operation.

[0097] (8) After ensuring that the welded parts are completely covered, the welding operation is completed and the system is initialized.

[0098] The above reconfigurable track, disassembly and assembly module, support frame, sliding module, robotic arm module, robotic arm support module, wire winding module, variable stiffness module, cylindrical lifting module, welding equipment module, driving rope and motor are only the preferred methods of the present invention. The track, lifting module unit, welding module unit and cylindrical lifting module realize reconfigurable modularization, the variable stiffness module adjusts the rope tension, and the wire winding module avoids rope interference, which improves the working space, flexibility and efficiency of the equipment as a whole. The present invention can be used in the field of lifting, grasping and welding of irregular workpieces, and can better control the end in real time to complete the welding process.

[0099] Although this specification is described according to implementation modes, not every implementation mode includes only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0100] Therefore, the above description is only a preferred embodiment of the present application and is not intended to limit the scope of implementation of the present application; that is, all equivalent changes made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. A reconfigurable modular flexible cable parallel robot for welding irregular workpieces, characterized in that: It includes a reconfigurable track unit, a support module, a sliding module, a winding module, a robot support module, a robot module, a cylinder hoisting module, a robot rope and a welding equipment module. The reconfigurable track unit is provided with a plurality of support modules arranged at intervals. The support modules are respectively provided with a winding module and a robot support module through sliding modules. The winding modules are two and arranged in parallel, one above and one below. The robot support module is provided with a robot module. The robot module includes a hoisting robot module and a welding robot module. The hoisting robot module is hoisted with a cylinder hoisting module for installing a workpiece through two robot ropes. The end of the welding equipment module is provided with a welding equipment module driven by two robot ropes. The driving process of the hoisting robot arm module is as follows: a robot arm rope is first led out from the lower winding module, guided by the winding pulley group on the upper winding module, bypasses the robot arm support module, and then passes through the hoisting robot arm module, and extends from the front end of the hoisting robot arm module to be connected to the lifting ring pulley module at the upper end of the cylinder hoisting module; another robot arm rope is led out from the upper winding module, bypasses the robot arm support module, passes through the hoisting robot arm module, and then extends from the front end of the hoisting robot arm module to be connected to the lifting ring pulley module at the lower end of the cylinder hoisting module; The driving process of the welding robot arm module: a robot arm rope is first led out from the lower winding module, guided by the winding pulley group on the upper winding module, bypassing the robot arm support module, and then passing through the hoisting robot arm module in sequence, and extending from the front end of the hoisting robot arm module to connect to the lifting ring pulley module at the upper end of the cylinder hoisting module; another robot arm rope is first led out from the upper winding module, bypassing the robot arm support module, passing through the hoisting robot arm module in sequence, and extending from the front end of the hoisting robot arm module to connect to the lifting ring pulley module at the lower end of the cylinder hoisting module; The hoisting robot arm module includes a robot arm outer frame for supporting and guiding the robot arm rope, one end of the robot arm outer frame is fixedly mounted on the robot arm support frame connecting shaft of the robot arm support module, the other end of the robot arm outer frame is fixedly mounted with a hemispherical pulley module, and a robot arm tensioning wheel and a variable stiffness module are installed in the robot arm outer frame; The hemispherical pulley module is composed of a U-shaped hinge module and a hemispherical pulley. The U-shaped hinge module is composed of a large circular ring base, a medium circular ring base, a small circular ring base, a long connecting shaft, and a short connecting shaft. The large circular ring base and the medium circular ring base are connected by the short connecting shaft, and the medium circular ring base and the small circular ring base are connected by the long connecting shaft. The middle of the hemispherical pulley is provided with an arc-shaped guide groove, and through holes for the robot arm rope to pass through are provided on both sides of the corresponding position of the arc-shaped guide groove; The variable stiffness module includes a variable stiffness inner connecting ring, on which a variable stiffness module ring outer frame and a variable stiffness module ring inner frame unit are mounted, an inner side surface of the variable stiffness module ring inner frame unit is provided with an insert block, and the inner side of the variable stiffness module ring outer frame is provided with an open slot for inserting the insert block, there are four variable stiffness module ring inner frame units, which are evenly distributed along the circumference of the variable stiffness inner connecting ring, and grooves are provided between the variable stiffness module ring inner frame units to adapt to the tension of the robot arm rope, and the outer side of the variable stiffness module ring inner frame unit is connected to the variable stiffness module ring outer frame through a spring.

2. The reconfigurable modular flexible cable parallel robot for welding irregular workpieces according to claim 1, characterized in that: The reconfigurable track unit is composed of reconfigurable tracks of varying numbers. The material of the reconfigurable track is a profile. Adjacent reconfigurable tracks are connected by movable hinges and can be assembled into reconfigurable track units of different shapes as needed. The reconfigurable track unit is a triangle, a quadrilateral, a pentagon or a hexagon.

3. The reconfigurable modular flexible cable parallel robot for welding irregular workpieces according to claim 1, characterized in that: The wire winding module includes a wire winding base, on which two wire winding end covers are installed in parallel, a wire winding connecting shaft is rotatably installed between the wire winding end covers, a plurality of wire winding rings are mounted on the wire winding connecting shaft, and the wire winding rings are connected and fixed by wire winding ring fixing shafts, a wire winding pulley group for supporting the rope is also installed on the wire winding base, and the rotation of the wire winding connecting shaft is driven by a motor on one side thereof.

4. The reconfigurable modular flexible cable parallel robot for welding irregular workpieces according to claim 1, characterized in that: The robot arm support module includes a robot arm support frame base, on which a robot arm support frame connecting shaft for installing the robot arm module is mounted through a support frame, and a robot arm support frame gear group is installed at one end of the robot arm support frame connecting shaft, and the rotation of the robot arm support frame gear group is driven by a robot arm support frame motor on one side thereof.

5. The reconfigurable modular flexible cable parallel robot for welding irregular workpieces according to claim 1, characterized in that: The cylindrical lifting module includes a cylindrical frame, and grooves arranged at intervals are evenly distributed in the outer circumferential direction of the cylindrical frame. Sliding rails are installed in the grooves, and through holes for installing the sliding rails are provided inside the grooves. A ring pulley module for connecting the rope of the robot arm is installed on the sliding rail, and the ring pulley modules form a parallel pulling form for two pairs. The ring pulley module consists of a ring base, a ring connecting shaft and a ring pulley, and an end connecting frame for installing a workpiece is installed at the upper end of the cylindrical frame.

6. The reconfigurable modular flexible cable parallel robot for welding irregular workpieces according to claim 1, characterized in that: The welding robot arm module includes two hingedly connected robot arm outer frames supporting and guiding robot arm ropes, and a robot arm tensioning wheel and a variable stiffness module are respectively installed in the robot arm outer frames. The bottom end of one robot arm outer frame is fixedly installed on the robot arm support frame connecting shaft of the robot arm support module, and the upper end of the other robot arm outer frame is installed with a robot arm connecting shaft. A welding equipment module is installed on the robot arm mounting shaft, and the welding equipment module includes a welding equipment module base and a welding equipment module welding gun.

7. A method for using a reconfigurable modular flexible cable parallel robot for welding irregular workpieces according to any one of claims 1 to 6, characterized in that: The specific steps are as follows: (1) System initialization: First, determine the position parameters of the workpiece to be welded, place the workpiece to be welded at a fixed position, adjust the parameters of each module, and input them into the control system host computer; (2) The host computer determines the position of the main area of ​​the workspace based on the position parameters of the workpiece, starts the servo motor in the winding mechanism, adjusts the rope to balance the tension according to the position of the mechanism, and each sliding module, robotic arm, robotic arm support module, spring, and welding equipment module are in a stable position; (3) During the movement of the welding equipment module, the tension sensor and the angle sensor collect data and output it to the host computer, so as to control the balance mechanism to adjust with the end movement and adapt to the stiffness of the spring to meet the overall stability and accuracy of the mechanism; (4) When performing welding tasks, the lifting module unit is used to fix the welded parts. The cylindrical lifting module at the end adjusts the position of the lifting point according to the welded parts, and cooperates with the reconfigurable track to meet the needs of supporting welded parts with different shapes and complex curved surfaces, thereby reducing the stiffness changes of the welded workpieces. (5) The welding equipment module controls the robot arm module and the welding gun with a total of three degrees of freedom through two ropes. The ropes pass through the winding module, the robot arm module, and then are connected to the end welding gun equipment module. The overall welding is carried out from bottom to top layer by layer. The gear set controls the angle of the robot arm module, and the rope controls the angle of the welding gun. Combined with the reconfigurable track, the welding gun can be freely controlled to reach the predetermined position. After setting the trajectory, irregular workpieces can be welded; (6) During general lifting operations, a parallel structure is adopted, with the cable exit point located in the middle and upper part of the overall mechanism. Different shapes of reconfigurable tracks are matched, and different numbers of sub-modules are installed to form a lifting structure with three cables, four cables, five cables or six cables. (7) When performing operations with high precision and high speed, the parallel structure is still used. Some submodules adjust the cable point position to the middle and lower part of the overall mechanism, and the other part remains in the middle and upper part of the overall mechanism. They cooperate with each other to form a pulling structure, thereby improving the speed of the overall mechanism operation. (8) After ensuring that the welded parts are completely covered, complete the welding operation and initialize the system.

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