A mobile rigid-flexible coupling welding robot system and method

Abstract

The application belongs to the technical field of industrial robots, and discloses a movable rigid-flexible coupling welding robot system and method, which comprises a movable base and a hydraulic lifting module arranged below a frame, realizes all-directional movement and lifting of the system, is provided with a transverse and longitudinal movement module, a posture adjustment module and a rotating platform in the frame, carries out two-stage pose adjustment of the robot to adapt to different workpiece geometries and weld characteristics, is provided with an outer facade welding auxiliary module on the side of the frame, realizes robot overturning to carry out outer facade welding, and is provided with a parallel flexible cable driven welding robot device in the rigid-flexible coupling welding robot module to carry out pose adjustment of a welding gun module and realize all-directional and rapid welding of complex welding parts. The application solves the problem that the working space of the welding robot is limited and the welding efficiency is difficult to improve in the prior art, has great space coverage and flexibility, and can realize various complex spot welding and arc welding tasks in typical fields such as automobile, ship manufacturing and steel structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of industrial robots, and particularly relates to a movable rigid-flexible coupling welding robot system and method. BACKGROUND

[0002] Welding is an industrial process that realizes the fixation of welding parts by high-temperature melting of metal. As one of the most important material forming and processing technologies in modern manufacturing, welding is widely used in the fields of automobile manufacturing, shipbuilding and steel structure. Traditional manual welding has the characteristics of labor-intensive and poor working environment. At the same time, the welding process will produce high-intensity arc light and harmful gas, so the welding operation has considerable risk. Welding robots can replace traditional manual welding methods and have the characteristics of stable welding quality and high productivity, showing broad application prospects.

[0003] The traditional welding robot base is fixed at a specific work station, and the working range is severely limited by the robot working space. In order to increase the working range of the welding robot, one existing method is to install the robot base on a guide rail to realize movement. However, since the robot can only move along the guide rail in single degree of freedom, its working range is still limited. Further, the robot is suspendedly installed on a gantry, and through the transverse movement of the gantry and the longitudinal movement of the robot on the gantry, the robot obtains a larger working range and can realize welding of large and medium-sized parts and long welds, which has been widely used in the field of shipbuilding. However, the working range of the existing welding robot system is still limited by the installation position of the guide rail, the gantry and the like and the working space of the robot body, it is difficult to realize full coverage of the working scene, and often manual assistance is needed for welding part placement or clamping, which limits the improvement of production efficiency. With the development of movable robots and related positioning and navigation technologies, the design of a movable welding robot base helps to improve the coverage rate of the welding robot system to the working scene and the production efficiency.

[0004] To meet the welding requirements of current shipbuilding, steel structure and other heavy industry with multi-variety, small batch and high differentiation, for workpieces with non-standardized geometric structure and welds with complex characteristics, complex welding processes and switching between multiple welding processes are often required. The serial rigid manipulator with high degree of freedom and high absolute positioning accuracy is widely used in welding operations. However, for welding tasks involving complex welding processes, the cumbersome inverse solution process may adversely affect welding efficiency. Due to the high repeatability, low inertia and fast response of parallel robots, they are particularly suitable for complex weld welding and switching between multiple welding processes. At the same time, the workspace of traditional parallel robots is limited, and the rigid-flexible coupling parallel robot driven by a rope has the advantages of large workspace, good dynamic performance and low required driving power, which is more suitable for high-intensity complex welding operation scenarios. In particular, the robot pose adjustment device can assist the robot in pose adjustment to adapt to different workpiece geometry and weld characteristics, and realize welding operation. Finally, the intelligent sensor system combined with multiple sensors helps to realize automatic welding of non-structured parts in unstructured environments.

[0005] Through the search of existing public technical literature, it is found that the Chinese invention patent with application number CN202311755464.9 discloses a robot arc welding workstation. The invention installs the welding robot base on the fixed station, and realizes the clamping and fixing of the welding part, the pose adjustment and the pre-stress application through the displacement mechanism. Although the invention helps to further improve the automation degree of arc welding, the robot workspace is limited and the welding part clamping and other work still need manual intervention, which is difficult to adapt to the welding operation of size and height differentiated workpieces.

[0006] The Chinese invention patent with application number CN202411544891.7 discloses a multi-plate node automatic welding equipment and its control method. The invention installs the welding assembly and the node clamp assembly on a lifting support bracket including an arc-shaped electric control sliding rail and a movable platform driven by a hydraulic cylinder, which can realize the vertical lifting and rotation angle adjustment of the welding assembly and the node clamp assembly. However, due to the limited degree of freedom of the lifting support bracket and the limitation of the installation position of the robot system, the size of the electric control sliding rail and the stroke of the hydraulic cylinder, the lifting support bracket is more suitable for simple, small and medium-sized parts standardized welds in structured environments.

[0007] A mobile omnidirectional welding robot is disclosed in Chinese patent application CN202411261203.6. The welding robot is installed above the frame, and the welding machine and the control unit can move relative to the frame in one degree of freedom. Although the robot system increases the welding range to some extent, the workspace coverage is still limited due to the lack of height variation of the robot base. SUMMARY

[0008] To solve the above-mentioned defects in the prior art, the purpose of the present application is to provide a mobile rigid-flexible coupling welding robot system and method. The welding robot system enables the welding robot to have strong omnidirectional autonomous mobility, thereby increasing the coverage of the work scene. The rigid-flexible coupling welding robot realizes efficient welding of non-standardized welding parts and complex welds, adapts to frequent switching between welding processes, and improves the welding efficiency of the robot system. The robot pose adjustment device realizes the adjustment of the pose of the welding robot while increasing its workspace. The sensor module realizes the positioning and navigation of the mobile base, the automatic control of the rigid-flexible coupling welding robot, and the intelligent pose adjustment, thereby solving the problem of limited welding robot workspace and difficult improvement of welding efficiency.

[0009] The present application is realized by the following technical solutions.

[0010] In one aspect of the present application, a mobile rigid-flexible coupling welding robot system is provided, comprising:

[0011] A mobile base module, comprising a frame module and a wheel module for omnidirectional movement within the welding work scene, for realizing the coverage of the work scene of the welding robot system;

[0012] A hydraulic lifting module, comprising a hydraulic cylinder and a kinematic pair component mounted on the mobile base module, for realizing the lifting of the frame of the welding robot system;

[0013] A system frame mounted above the hydraulic lifting module, for supporting the robot lateral movement module, the robot longitudinal movement module, the facade welding auxiliary module, the robot pose adjustment module, the robot rotation platform module, and the rigid-flexible coupling welding robot module, to construct the overall framework of the system;

[0014] A rigid-flexible coupling welding robot module, which is a parallel flexible cable driven welding robot device, for adjusting the pose of the welding torch module and realizing omnidirectional welding of complex welding parts;

[0015] A robot longitudinal movement module, comprising a ball screw module and a kinematic pair component, for realizing the longitudinal position adjustment and roll angle adjustment of the welding robot device;

[0016] The robot lateral movement module is a movement platform composed of two-stage guide assemblies and driving devices, and is used for realizing lateral position adjustment of the welding robot device located below the robot lateral movement module.

[0017] The facade welding auxiliary module is an expandable mechanism which is flipped along the outside of the system framework, and realizes the alternate transmission of the welding robot device between the robot lateral movement module and the underside of the expandable mechanism through at least two groups of driving systems based on electromagnetic clutches, thereby assisting in realizing the facade welding operation.

[0018] The robot posture adjustment module is located at the underside of the robot lateral movement module, and is a 3-RPS parallel mechanism which realizes the adjustment of two rotation amounts and one translation amount of the welding robot device by controlling the motion amounts of three motion branches.

[0019] The robot rotation platform module is located between the robot posture adjustment module and the rigid-flexible coupling welding robot module, and is used for realizing the adjustment of one rotation amount of the rigid-flexible coupling welding robot module.

[0020] The sensor system module is used for the positioning of the movable base module, and the motion amount monitoring of the robot lateral movement module, the robot longitudinal movement module, the facade welding auxiliary module, the robot posture adjustment module, the robot rotation platform module and the rigid-flexible coupling welding robot module.

[0021] As a preferred embodiment, the system framework is a truss structure which comprises four symmetrically installed structural support assembly and lateral link assembly, the movable base module and the hydraulic lifting module are sequentially installed at the underside of the structural support assembly, the robot longitudinal movement module is vertically installed in the middle of the structural support assembly, the robot lateral movement module is located in the middle of the system framework and is installed at the underside of the robot longitudinal movement module, and the facade welding auxiliary module is hinged at the side of the structural support assembly and is connected to the lateral link assembly through a link.

[0022] As a preferred embodiment, the robot lateral movement module comprises a first-stage platform panel connected to the ball screw module in the robot longitudinal movement module, the first-stage platform panel is provided below with a lateral movement module driving assembly and a lateral movement module guide assembly, the lateral movement module driving assembly is a long-stroke ball screw module, and the lateral movement module guide assembly comprises two-stage guide assemblies.

[0023] The first-stage guide assembly comprises two first guide rails and a first-stage movement platform, and the first-stage movement platform is fixedly installed on the screw nut of the lateral movement module driving assembly.

[0024] The secondary guide assembly comprises two second guide rails located outside the first guide rail and a secondary platform panel, the secondary platform panel is connected to the lower surface of the primary moving platform through the second guide rail slider to drive the secondary platform panel.

[0025] As preferred, the facade welding auxiliary module comprises a second ball screw mounted on the lateral link assembly of the system frame, and a connecting rod articulated with the slider of the second ball screw module, the connecting rod is articulated with the expandable platform, the expandable platform is articulated with the front side of the structural support assembly through a rotating shaft, and the expandable platform realizes the overturning movement around the rotating shaft under the driving of the second ball screw module.

[0026] As preferred, two sets of tertiary platform panel driving modules and two sets of tertiary platform panel guide modules are arranged on the lower surface of the expandable platform and the secondary platform panel of the robot lateral movement module, the tertiary platform panel is connected to the guide rail slider of the tertiary platform panel guide module and moves linearly along the lower surface of the expandable platform and the secondary platform panel with one degree of freedom;

[0027] The tertiary platform panel driving module is connected with the driven rack on the tertiary platform panel through the driving gear connected with the first step motor; the electromagnetic clutch assembly between the output shaft of the first step motor and the driving gear is attracted or disconnected to realize the alternate engagement of the driven rack with the driving gears of the two sets of driving devices and the motion transmission.

[0028] As preferred, the facade welding auxiliary module further comprises at least four sets of tertiary platform panel limiting devices, the tertiary platform panel limiting device comprises a fifth guide groove respectively mounted on the edge of the secondary platform panel of the robot lateral movement module and the expandable platform, the fifth guide groove is fixedly connected with a second step motor, the sliding limiting assembly inside the second step motor driving gear engages with the rack to drive the sliding limiting assembly with a baffle to move up and down along the fifth guide groove, thereby limiting the tertiary platform panel.

[0029] As preferred, the robot posture adjusting module comprises three motion branches and their kinematic pair components connected with the tertiary platform panel of the facade welding auxiliary module, a folding electric cylinder is mounted on each of the three motion branches to constitute a driving pair, the three motion branches are connected with a fourth moving platform, the fourth moving platform is connected with a robot rotating platform module, and the robot posture adjusting module has two rotational degrees of freedom and one translational degree of freedom.

[0030] As preferred, the robot rotating platform module comprises a servo drive motor connected to the fourth moving platform of the robot posture adjusting module, an output shaft flange of the servo drive motor is connected to a motor output shaft flange, and the motor output shaft flange passes through a thrust self-aligning roller bearing to connect a fifth rotating platform; the robot rotating platform module has one rotational degree of freedom.

[0031] As preferred, the rigid-flexible coupling welding robot module comprises a robot static platform located below the five-stage rotating platform of the robot rotating platform module, and a robot dynamic platform parallel to the robot static platform, a flexible motion branch chain is formed by connecting the robot static platform and the robot dynamic platform through a cable system; a radial stretching module and a variable stiffness tensioning module are nested between the robot static platform and the robot dynamic platform to form a rigid motion branch chain; a welding torch module is connected to the lower side of the robot dynamic platform;

[0032] Each cable system drives the cable drum to rotate through the cable drive servo motor, and drives the parallel cable branch chain around the cable drum to realize contraction and release;

[0033] The radial stretching module drives the nut block and the first sleeve to rotate through the third stepping motor driven screw rod, so as to realize the stretching of the rigid motion branch chain;

[0034] The variable stiffness tensioning module realizes the tensioning of the cable connected to the robot dynamic platform and the robot static platform at the bottom of the variable stiffness tensioning module through the expansion and contraction of the screw spring mechanism connected below the radial stretching module, and adjusts the stiffness of the rigid motion branch chain by controlling the number of springs connected to the screw spring mechanism.

[0035] In another aspect of the application, a welding method of a mobile rigid-flexible coupling welding robot of the system is provided, characterized in that it comprises:

[0036] S1, the welding robot system is initialized, the sensor system module is tested, and the system is calibrated;

[0037] S2, the mobile base module positions the robot and maps the scene based on the sensor system module, and plans the motion trajectory of the welding robot system;

[0038] S3, the hydraulic lifting module drives the system frame to vertically ascend, the local welding part point cloud data is obtained by the sensor system module on the system frame, and the high-quality welding part point cloud is obtained by a multi-view three-dimensional reconstruction method;

[0039] S4, for large and complex welding parts, steps S2-S3 are repeatedly executed, and a plurality of local welding part point clouds are registered until the welding part point cloud reconstruction is completed;

[0040] S5, according to the geometric characteristics of the welding part, the welding seam generation is carried out in the welding manufacturing system deployed in the cloud;

[0041] S6, a plurality of welding seams are grouped and sorted according to the welding seam characteristics, the workpiece geometric shape and the task priority; the welding seams related to the external facade welding are separated from other welding seams, and the welding seams with a length exceeding the working space of the mobile base module of the welding robot system in the static state are separated from other welding seams;

[0042] S7, determining whether to use the facade welding auxiliary module to drive the three-level platform panel, the robot pose adjustment module, the robot rotating platform module and the rigid-flexible coupling welding robot module on the underside thereof for 90° overturning according to whether the group of welds is a facade welding task;

[0043] S8, generating a welding gun trajectory according to weld characteristics and welding robot system kinematics, combining a scene map and a weld point cloud, and driving a system framework to ascend and descend to realize obstacle avoidance by a hydraulic lifting module;

[0044] S9, using a robot longitudinal movement module and a robot transverse movement module to perform preliminary pose adjustment of the robot in vertical lifting, horizontal movement and transverse rolling movement;

[0045] using a robot pose adjustment module and a robot rotating platform module to perform fine adjustment of the robot pose in transverse rolling movement, pitch movement, yaw movement and vertical lifting;

[0046] S10, according to the welding gun trajectory, the robot longitudinal movement module, the robot transverse movement module, the robot pose adjustment module, the robot rotating platform module and the rigid-flexible coupling welding robot module cooperatively perform continuous welding operation; the robot pose adjustment module and the robot rotating platform module cyclically perform pose adjustment;

[0047] S11, for a weld with a length exceeding the working space of the welding robot system base in a stationary state, it is necessary to perform segmentation and repeated execution:

[0048] i. steps S2-S3;

[0049] ii. steps S8-S10, long weld welding is realized by movable base module movement assistance;

[0050] S12, after completing a weld, steps S8-S11 are repeated until a group of welds is completed;

[0051] S13, after completing a group of welds, steps S7-S11 are repeated until all welds are completed.

[0052] The present application has the following beneficial effects due to the above technical solutions:

[0053] 1. The present application adopts a parallel flexible cable driven rigid-flexible coupling welding robot, which, compared with a traditional serial welding robot, reduces complex joint transmission, has the advantages of lightweight, fast response and low power consumption. The rigid-flexible coupling welding robot module adopts a winch synchronous winding and unwinding parallel flexible cable to realize automatic cable force distribution while reducing the number of motors and the control difficulty.

[0054] 2. The rigid-flexible coupling welding robot module of the present application adopts a radial stretching module and a variable stiffness tensioning module to realize rigid branched chain radial expansion and contraction and flexible cable stiffness adjustment, to realize flexible cable tensioning while ensuring that the robot power consumption and the end load dynamic match, to improve the welding efficiency of complex welds, and to be suitable for operation scenes that require frequent switching of multiple welding processes.

[0055] 3. The robot transverse and longitudinal movement module in the present application constitutes a first-level regulation platform, which is used for preliminary adjustment of the pose of the robot in the horizontal and vertical directions, and significantly expands the operation range; the pose adjustment module and the rotating platform module constitute a second-level regulation platform, which realizes fine adjustment of three rotation amounts and one movement amount of the robot base; the two-stage platforms cooperate, so that the rigid-flexible coupling welding robot can accurately adapt to the pose adjustment of the welding torch trajectory.

[0056] 4. The outer facade welding auxiliary module in the present application realizes the transverse movement and overturning movement of the welding robot and its pose adjustment device based on the on-off control principle of the electromagnetic clutch, in combination with the alternative operation of the double sets of driving devices, to assist in completing the outer facade welding task.

[0057] 5. The welding robot system in the present application adopts an omnidirectional movable base, which expands the operation range of the system; by integrating a hydraulic lifting module, the system realizes overall lifting, enhances the obstacle avoidance ability of the system, and at the same time increases the spatial operation range of the system, effectively avoids structural interference, and improves the universality and robustness of the system. BRIEF DESCRIPTION OF DRAWINGS

[0058] The accompanying drawings, which are included to provide a further understanding of the present application and constitute a part of this application, do not constitute an inappropriate limitation on the present application, and in the drawings:

[0059] Figure 1 is a schematic diagram of the overall structure of the present application;

[0060] Figure 2 is a schematic diagram of the external structure of the movable base;

[0061] Figure 3 is a schematic diagram of the internal structure of the movable base;

[0062] Figure 4 is an exploded view of the wheel module and the driving module of the movable base;

[0063] Figure 5 is a schematic diagram of the structure of the hydraulic lifting module;

[0064] Figure 6 is a schematic diagram of the framework structure of the robot system;

[0065] Figure 7 is a schematic diagram of the structure of the robot transverse and longitudinal movement module;

[0066] Figure 8 is a partial view of the hinge connection structure of the robot transverse and longitudinal movement module;

[0067] Figure 9 is a schematic view of the facade welding auxiliary module structure;

[0068] Figure 10 is a schematic view of the drive module structure of the facade welding auxiliary module;

[0069] Figure 11 is a schematic view of the limiting device structure of the facade welding auxiliary module;

[0070] Figure 12 is a schematic view of the robot pose adjustment module structure;

[0071] Figure 13 is an exploded view of the robot rotating platform module;

[0072] Figure 14 is a schematic view of the overall structure of the rigid-flexible coupling welding robot module;

[0073] Figure 15 is a schematic view of the flexible cable drive system structure in the rigid-flexible coupling welding robot module;

[0074] Figure 16 is a schematic view of the flexible cable system structure in the rigid-flexible coupling welding robot module;

[0075] Figure 17 is a schematic view of the radial extension module structure in the rigid-flexible coupling welding robot module;

[0076] Figure 18 is a schematic view of the internal structure of the radial extension module;

[0077] Figure 19 is a schematic view of the variable stiffness tensioning module structure in the rigid-flexible coupling welding robot module;

[0078] Figure 20 is a flowchart of the operation method of the movable rigid-flexible coupling welding robot system.

[0079] The reference signs in the drawings are as follows:

[0080] 1. Movable base module;

[0081] 101. First support panel;

[0082] 102. Vehicle frame module, 102-1. Vehicle beam assembly, 102-2. Support column, 102-3. Second support panel, 102-4. Chassis assembly;

[0083] 103. Wheel module, 103-1. Mecanum wheel side plate, 103-2. Roller shaft, 103-3. Roller, 103-4. Support shaft, 103-5. Mecanum wheel support;

[0084] 104. Drive module, 104-1. First drive motor, 104-2. Transmission module side plate, 104-3. Driving gear, 104-4. Driven gear, 104-5. Output shaft, 104-6. Opposite side plate, 104-7. Transmission module box;

[0085] 105. Battery module;

[0086] 2. Hydraulic lifting module;

[0087] 201. Hydraulic cylinder base, 202. Hydraulic cylinder, 203. Output rod, 204. First hinge assembly, 205. Second hinge assembly, 206. Third hinge assembly;

[0088] 3. System frame;

[0089] 301. Structural support assembly, 302. Transverse link assembly, 303. Third ball screw module;

[0090] 4. Robot transverse movement module;

[0091] 401. First level platform panel, 402. First support assembly;

[0092] 403. Transverse movement module drive assembly, 403-1. Second drive motor, 403-2. First coupling, 403-3. Screw rod, 403-4. Screw rod nut;

[0093] 404. Transverse movement module guide assembly, 404-1. First guide rail, 404-2. Moving platform, 404-3. Second guide rail, 404-4. Second level platform panel, 404-5. Second guide rail slider;

[0094] 5. Robot longitudinal movement module;

[0095] 501. First ball screw module, 501-1. Ball screw slider;

[0096] 6. Facade welding auxiliary module;

[0097] 601. Second ball screw module, 602. Expandable platform, 603. Connecting rod, 604. Third level platform panel;

[0098] 605. Third stage platform panel driving module, 605-1. Driving gear, 605-2. Driven rack, 605-3. First stepper motor, 605-4. Bearing, 605-5. Electromagnetic clutch motion input end, 605-6. Electromagnetic attraction component, 605-7. Spring sheet, 605-8. Electromagnetic clutch motion output end;

[0099] 606. Third stage platform panel guiding module, 606-1. Third guide rail, 606-2. First limiting mechanism, 606-3. Fourth guide rail, 606-4. Second limiting mechanism;

[0100] 607. Third stage platform panel limiting device, 607-1. Second stepper motor, 607-2. Gear, 607-3. Fifth guide slot, 607-4. Sliding limiting assembly, 607-5. Rack, 607-6. Baffle;

[0101] 608. Rotation shaft;

[0102] 7. Robot pose adjustment module;

[0103] 701. Fourth stage moving platform, 702. Second support assembly, 703. Turn-back electric cylinder, 704. Spherical hinge support assembly;

[0104] 8. Robot rotating platform module;

[0105] 801. Servo driving motor, 802. Motor output shaft flange, 803. Thrust aligning roller bearing, 804. First thrust bearing support, 805. Second thrust bearing support, 806. Fifth stage rotating platform;

[0106] 9. Rigid-flexible coupling welding robot module;

[0107] 901. Robot static platform, 901-1. Through hole, 901-2. Fixing bolt set;

[0108] 902. Robot moving platform, 902-1. Flexible cable sling, 902-2. First hooke joint assembly;

[0109] 903. Flexible cable driving system module, 903-1. Support base, 903-2. Flexible cable driving servo motor, 903-3. Synchronous pulley assembly, 903-4. Flexible cable drum;

[0110] 904. Flexible cable system, 904-1. First guide wheel, 904-2. First guide wheel support, 904-3. Second guide wheel, 904-4. Second guide wheel support, 904-5. First flexible cable, 904-6. Second flexible cable;

[0111] 905. Radial extension module; 905-1. Second Hooke hinge assembly; 905-2. Third stepper motor; 905-3. Flange; 905-4. Lead screw; 905-5. Second coupling; 905-6. Fifth guide rail; 905-7. First sleeve; 905-8. Stop; 905-9. Nut slider;

[0112] 906. Variable stiffness tensioning module; 906-1. Second sleeve; 906-2. Outer ring of first sleeve; 906-3. Outer ring of second sleeve; 906-4. Threaded rod; 906-5. Spring; 906-6. Double-ended nut;

[0113] 907. Welding torch module;

[0114] 10. Sensor system module;

[0115] 1001. Depth camera; 1002. LiDAR; 1003. Welding component scanning vision sensor; 1004. First laser rangefinder; 1005. Second laser rangefinder; 1006. First angle sensor; 1007. Third laser rangefinder; 1008. Second angle sensor; 1009. Fourth laser rangefinder; 1010. Third angle sensor; 1011. Cable displacement sensor. Detailed Implementation

[0116] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0117] like Figure 1 As shown, this embodiment provides a mobile rigid-flexible coupling welding robot system, including a mobile base module 1, a hydraulic lifting module 2, a system frame 3, a robot lateral movement module 4, a robot longitudinal movement module 5, an exterior welding auxiliary module 6, a robot posture adjustment module 7, a robot rotation platform module 8, a rigid-flexible coupling welding robot module 9, and a sensor system module 10.

[0118] Wherein, the movable base module 1 and the hydraulic lifting module 2 are sequentially installed on the lower side of the system frame 3 to realize the omnidirectional movement and vertical lifting of the system frame 3; the robot transverse movement module 4 is horizontally arranged inside the system frame 3 to drive the robot to move transversely, which is used to realize the transverse position adjustment of the welding robot device located below; the robot longitudinal movement module 5 is vertically installed inside the system frame 3 to drive the robot to vertically lift, which is used to realize the longitudinal position adjustment and roll angle adjustment of the welding robot device to adapt to different sizes of welding parts; the robot transverse movement module 4 and the robot longitudinal movement module 5 are connected through a hinge mechanism. The above modules are used to realize the preliminary pose adjustment of the rigid-flexible coupling welding robot module 9 to realize the obstacle avoidance of the robot system and ensure a larger welding operation range and space coverage.

[0119] The facade welding auxiliary module 6 is installed on the outer side of the middle part of the system frame 3, which includes a guide module connected to the lower side of the robot transverse movement module 4 and an expandable module installed on the outer side of the middle part of the system frame 3. Through the guide module and the expandable module, the auxiliary welding robot is realized 90° flip to facilitate the robot to perform the facade welding task.

[0120] The robot pose adjustment module 7 and the robot rotating platform module 8 are sequentially installed on the lower side of the robot transverse movement module 4. Among them, the robot pose adjustment module 7 has two rotational degrees of freedom and one translational degree of freedom; the robot rotating platform module 8 has one rotational degree of freedom; the robot transverse movement module 4, the robot longitudinal movement module 5, the robot pose adjustment module 7 and the robot rotating platform module 8 form a two-stage pose adjustment device of the welding robot, which realizes the five degrees of freedom pose adjustment of the rigid-flexible coupling welding robot module 9 to increase its operation range and adapt to workpieces and welds with different geometric characteristics.

[0121] The rigid-flexible coupling welding robot module 9 is installed on the lower side of the robot rotating platform module 8; it drives the lower dynamic platform 902 of the robot through the flexible cable driving system module 903, further drives the welding gun module 907 connected to the lower side of the dynamic platform 902, and realizes the all-around welding operation of the complex welding part.

[0122] The sensor system module 10 is installed on the movable base module 1, the robot transverse movement module 4, the robot longitudinal movement module 5, the facade welding auxiliary module 6, the robot pose adjustment module 7, the robot rotating platform module 8 and the rigid-flexible coupling welding robot module 9, which is used for positioning the movable base module 1 and monitoring the movement of each module.

[0123] As Figure 2As shown, the movable base module 1 of the embodiment includes four movable bases, and each movable base is a Mecanum wheel omnidirectional mobile platform driven by four independent motors, which includes a first support panel 101, a frame module 102, a wheel module 103, a drive module 104, a battery module 105, a depth camera 1001 and a laser radar 1002.

[0124] As shown, the first support panel 101 is installed on the upper side of the frame module 102, used to connect the hydraulic lifting module 2 and install the depth camera 1001 and the laser radar 1002; the wheel module 103 and the transmission module 104 are installed on the lower side of the frame module 102; and the battery module 105 is installed inside the middle part of the frame module 102.

[0125] As shown, Figure 3 the frame module 102 includes a beam assembly 102-1, a support column 102-2, a second support panel 102-3 and a chassis assembly 102-4. The beam assembly 102-1 is located on both sides of the frame module 102, connected by bolts to the support column 102-2 installed on the inner side of the beam assembly 102-1, and the lower side of each support column 102-2 is connected to the second support panel 102-3. The chassis assembly 102-4 is fixedly installed on the second support panel 102-3, and four sets of drive modules 104 are installed on the lower side of the second support panel 102-3 and inside the chassis assembly 102-4; the drive module 104 is installed corresponding to the wheel module 103; in addition, the battery module 105 is installed on the second support panel 102-3 to supply power to the drive module 104.

[0126] As shown, Figure 4 the wheel module 103 and the drive module 104 are installed in a central symmetrical manner; the wheel module 103 is a Mecanum wheel mechanism, which includes two Mecanum wheel side plates 103-1, and there are a plurality of roller shafts 103-2 installed along the circumference inside the two Mecanum wheel side plates 103-1, and a roller 103-3 is concentrically installed on each roller shaft 103-2; in addition, there are a plurality of support shafts 103-4 installed along the circumference inside the two Mecanum wheel side plates 103-1; further, a Mecanum wheel support 103-5 is installed at the center inside the two side plates, which is a cylinder with holes and keyways machined inside; the motor output shaft of the drive module 104 is concentric with the inner hole of the Mecanum wheel support 103-5 and connected by a flat key; the roller shaft 103-2, the support shaft 103-4 and the Mecanum wheel support 103-5 are all installed on the Mecanum wheel side plate 103-1 by bolts.

[0127] As shown, Figure 4As shown, the drive module 104 includes a first drive motor 104-1 and a transmission module. The first drive motor 104-1 is mounted on the transmission module side plate 104-2 to realize power input and is connected to the drive gear 104-3. The driven gear 104-4 is mounted on the output shaft 104-5, and the drive gear 104-3 meshes with the driven gear 104-4 for transmission. In addition, the transmission module side plate 104-2 and the opposite side plate 104-6 are mounted on both sides of the transmission module housing 104-7.

[0128] like Figure 5 As shown, the hydraulic lifting module 2 in this embodiment includes four hydraulic cylinder systems and corresponding hinge assemblies. The hydraulic cylinder system includes a hydraulic cylinder base 201, a hydraulic cylinder 202, and a hydraulic cylinder output rod 203 mounted on the first support panel 101. The hinge module includes a first hinge assembly 204, a second hinge assembly 205, and a third hinge assembly 206 sequentially mounted on the hydraulic cylinder output rod 203. The second hinge assembly 205 and the first hinge assembly 204 form a first rotating joint, and the second hinge assembly 205 and the third hinge assembly 206 form a second rotating joint. In particular, the rotation axes of the first rotating joint and the second rotating joint are perpendicular. In addition, the third hinge assembly 206 is connected to the system frame 3 by bolts.

[0129] Therefore, the overall lifting and lowering movement of the system frame 3 can be achieved through the cooperation of four sets of hydraulic lifting modules 2, so as to avoid obstacles for the robot system according to the working environment and changes in the size of the welded parts, and prevent interference.

[0130] like Figure 6 As shown, the system frame 3 in this embodiment is a truss structure, which includes four symmetrically installed structural support components 301. The bottom of each structural support component 301 is connected to the third hinge component 206 of the hydraulic lifting module 2. The robot lateral movement module 4 and the robot longitudinal movement module 5 are mounted in the middle of the structural support component 301. The outer side of the middle of the structural support component 301 is connected to the exterior welding auxiliary module 6 through a hinge mechanism to achieve rotational connection relative to the system frame 3. The lowest point of the vertical movement of the exterior welding auxiliary module 6 and the robot lateral movement module 4 are on the same plane.

[0131] In addition, it also includes transverse link assemblies 302 at the top and middle of the structural support assembly 301 frame for holding the system frame 3; the structural support assembly 301 and the transverse link assembly 302 are connected by bolts to form the system frame 3 together.

[0132] like Figure 6As shown, the third ball screw module 303 for driving the welding scan visual sensor 1003 is installed on the lowermost transverse link assembly 302; the first ball screw module 501 for driving the robot longitudinal movement module 5 is vertically installed on each structural support assembly 301 frame; the second ball screw module 601 for driving the facade welding auxiliary module 6 is installed on the transverse link assembly 302 installed on the upper middle of the system frame 3.

[0133] As shown in Figure 7 , Figure 8 The robot transverse movement module 4 of the embodiment includes a primary platform panel 401, a first support assembly 402, a transverse movement module driving assembly 403, and a transverse movement module guiding assembly 404. Four first support assemblies 402 are installed on the upper side of the primary platform panel 401; the four first support assemblies 402 correspond to the first ball screw module 501 in the robot longitudinal movement module 5 respectively, and are connected with the ball screw slider 501-1 through bolts.

[0134] The transverse movement module driving assembly 403 is located on one side below the primary platform panel 401 and is arranged along the length direction of the lower side of the primary platform panel 401; the transverse movement module driving assembly 403 is a long-stroke ball screw module, which includes a second driving motor 403-1, a first coupling 403-2, a screw 403-3, and a screw nut 403-4; wherein the second driving motor 403-1 drives the screw 403-3 to rotate through the first coupling 403-2, and the screw nut 403-4 sleeved thereon converts the rotational motion of the screw 403-3 into its own translational motion.

[0135] In order to maximize the system operation range, the primary platform panel 401 is designed to be relatively large in size, so the screw 403-3 in the transverse movement module driving assembly 403 is correspondingly longer; in order to improve the motion accuracy and stability of the robot system, two-stage guiding assemblies are further designed:

[0136] The first-stage guiding assembly includes the primary platform panel 401, a moving platform 404-2;

[0137] The second-stage guiding assembly includes two second guide rails 404-3, a second-stage platform panel 404-4, and a second guide rail slider 404-5.

[0138] The mobile platform 404-2 is fixedly installed on the screw nut 403-4 by bolts or buckles, so as to realize the driving of the mobile platform 404-2 in a single degree of freedom direction by the horizontal moving module driving assembly 403; further, the mobile platform 404-2 is fixedly installed on four sliding blocks installed on the two first guide rails 404-1 by bolts, so as to realize the guiding of the mobile platform 404-2 in a single degree of freedom direction; therefore, under the driving of the screw nut 403-4, the mobile platform 404-2 moves along the first guide rail 404-1 in a translational motion.

[0139] The secondary guiding assembly includes two second guide rails 404-3 located outside the screw rod 403-3, and the two second guide rails 404-3 are installed on the lower side of the primary platform panel 401 and parallel to the installation direction of the screw rod 403-3; further, the mobile platform 404-2 and the secondary platform panel 404-4 are connected by bolt groups to realize the driving of the secondary platform panel 404-4; in particular, the secondary platform panel 404-4 is fixedly connected with the second guide rail sliding block 404-5 installed on the second guide rail 404-3 by bolts, so as to realize the guiding of the second guide rail 404-3 to the motion of the secondary platform panel 404-4, and further realize the accurate long-stroke relative motion between the primary platform panel 401 and the secondary platform panel 404-4.

[0140] The secondary platform panel 404-4 moves in a single degree of freedom along the direction of the horizontal moving module guiding assembly 404 under the driving of the horizontal moving module driving assembly 403; the first laser ranging sensor 1004 is installed on the two sides of the primary platform panel 401 respectively, so as to realize the monitoring of the displacement of the secondary platform panel 404-4.

[0141] As shown in Figure 7 , the robot longitudinal moving module 5 of the embodiment includes four first ball screw modules 501, and the installation positions of the four first ball screw modules 501 in the frame are as shown in Figure 6 ; as shown in Figure 8 , the ball screw sliding block 501-1 of the first ball screw module 501 is fixedly connected with the first support assembly 402, so that the robot longitudinal moving module 5 is rotationally connected with the robot horizontal moving module 4; the second laser ranging sensor 1005 is installed on the horizontal connecting rod assembly 302 respectively, so as to realize the monitoring of the displacement and the inclination of the primary platform panel 401.

[0142] For the motion of the four ball screw modules 501: the displacement of the left two screw rods is consistent, which is recorded as displacement I, and the displacement of the right two screw rods is consistent, which is recorded as displacement II; the relative difference between the two displacement values is used to control the rotation of the primary platform panel 401, i.e. the roll motion, so as to realize the preliminary control of the posture of the rigid-flexible coupling welding robot module 9.

[0143] Specifically, in this embodiment, a two-level robot pose adjustment control mechanism is defined, wherein the robot lateral movement module 4 and the robot longitudinal movement module 5 serve as the first-level robot pose adjustment device to realize the initial adjustment of the welding robot's posture, namely, horizontal movement, vertical lifting and rolling motion.

[0144] like Figure 9 , Figure 10 , Figure 11 As shown, the exterior welding auxiliary module 6 in this embodiment includes a second ball screw module 601, a deployable platform 602, a connecting rod 603, a three-stage platform panel 604, a three-stage platform panel drive module 605, a three-stage platform panel guide module 606, a three-stage platform panel limiting device 607, and a rotating shaft 608. The second ball screw module 601, the connecting rod 603, and the deployable platform 602 form a crank-slider mechanism; wherein, as... Figure 9 As shown, the second ball screw module 601 is mounted on the transverse connecting rod assembly 302. The slider of the second ball screw module 601 is connected to the connecting rod 603 via a hinge. The connecting rod 603 is connected to the deployable platform 602 via a hinge. The deployable platform 602 is connected to the front support of the structural support assembly 301 via a rotating shaft 608 machined on its lower side. Therefore, under the drive of the second ball screw module 601, the deployable platform 602 can achieve a rotating motion around the rotating shaft 608 relative to the system frame 3. A first angle sensor module 1006 is installed at the hinge connection between the rotating shaft 608 and the front support of the structural support assembly 301 to monitor the rotation angle of the deployable platform 602.

[0145] Furthermore, the exterior welding auxiliary module 6 includes two sets of tertiary platform panel drive modules 605, which are fixedly installed at the center of the lower surface of the deployable platform 602 and the secondary platform panel 404-4, respectively. In addition, it includes two sets of tertiary platform panel guide modules 606, which are located on both sides of the lower surface of the deployable platform 602 and the secondary platform panel 404-4, respectively. Finally, four sets of tertiary platform panel limiting devices 607 are installed on one side of the deployable platform 602 and the secondary platform panel 404-4, and pass through their upper and lower surfaces, to limit the tertiary platform panel 604 that moves with a single degree of freedom on the lower side.

[0146] Specifically, the three-level platform panel drive module 605 includes a drive gear 605-1, a driven rack 605-2, and a first stepper motor 605-3. The driven rack 605-2 alternately meshes with the drive gears 605-1 of the two drive devices to achieve motion transmission. The drive gear 605-1 is mounted on the output shaft of the first stepper motor 605-3, and the driven rack 605-2 is mounted on the upper surface of the three-level platform panel 604 by bolts.

[0147] The third-level platform panel guiding module 606 comprises a third guide rail 606-1, a first limiting mechanism 606-2, a fourth guide rail 606-3 and a second limiting mechanism 606-4. The third-level platform panel 604 is installed on the slider of the third guide rail 606-1 or the fourth guide rail 606-3, so as to realize the single-degree-of-freedom movement of the third-level platform panel 604 under the expandable platform 602 and the second-level platform panel 404-4, and further ensure the linear motion accuracy of the third-level platform panel 604.

[0148] The upper side of the third-level platform panel 604 of the embodiment is fixed with four sliders and driven racks 605-2 in sliding connection with the third guide rail 606-1 or the fourth guide rail 606-3 through bolts, so that the driven racks 605-2 are driven to move linearly by the driving gear 605-1 installed on the first step motor 605-3, thereby realizing the movement of the third-level platform panel 604.

[0149] In particular, as shown in Figure 9 , the first limiting mechanism 606-2 and the second limiting mechanism 606-4 are used to lock the movement of one side of the third-level platform panel 604; in particular, if the third-level platform panel 604 is located under the second-level platform panel 404-4, the first limiting mechanism 606-2 is used to limit the movement freedom of the back side of the third-level platform panel 604, and if the third-level platform panel 604 is located under the expandable platform 602, the second limiting mechanism 606-4 is used to limit the movement freedom of the front side of the third-level platform panel 604.

[0150] The third-level platform panel driving module 605 of the embodiment comprises two sets of driving devices, which are installed under the second-level platform panel 404-4 and the expandable platform 602, respectively, as shown in Figure 9 ; in particular, as shown in Figure 9 , Figure 10 , the first step motor 605-3 and the driving gear 605-1 are installed at the centers of the lower surfaces of the second-level platform panel 404-4 and the expandable platform 602, respectively, and the bearings 605-4 are installed on the two shafts on the side surface of the driving gear 605-1. In particular, an electromagnetic clutch assembly is installed between the output shaft of the first step motor 605-3 and the driving gear 605-1, which comprises an electromagnetic clutch movement input end 605-5, an electromagnetic attraction component 605-6, a spring 605-7 and an electromagnetic clutch movement output end 605-8; the electromagnetic clutch movement input end 605-5 is connected with the output shaft of the first step motor 605-3, and the electromagnetic clutch movement output end 605-8 is connected with the shaft of the driving gear 605-1.

[0151] Specifically, when the electromagnetic clutch assembly is powered, the electromagnetic attraction component 605-6 attracts the motion input part 605-5 and the motion output part 605-8, realizing the transmission of the driving device motion; when the electromagnetic clutch assembly is powered off, the elastic sheet 605-7 rebounds, the motion input part 605-5 is disconnected with the motion output part 605-8, cutting off the transmission of the driving device motion; therefore, through the two working modes of the electromagnetic clutch assembly powered attraction and powered-off release, the first step motor 605-3 realizes the alternate transmission to the driving gear 605-1.

[0152] Next, taking the movement of the tertiary platform panel 604 from the lower side of the secondary platform panel 404-4 to the lower side of the deployable platform 602 as an example, the working process of the movement of the tertiary platform panel 604 in the outer facade welding auxiliary module 6 is shown as follows:

[0153] The electromagnetic clutch assembly in the tertiary platform panel driving module 605 on the lower side of the secondary platform panel 404-4 is attracted, under the driving of the first step motor 605-3 in the tertiary platform panel driving module 605 on the lower side of the secondary platform panel 404-4, the tertiary platform panel 604 leaves the first limiting mechanism 606-2 and moves along the third guide rail 606-1 located on the lower side of the secondary platform panel 404-4; further, the upper side of the tertiary platform panel 604 is connected with the fourth guide rail 606-3 on the lower side of the deployable platform 602 through the sliding of the first two sliders, at this time, the driven rack 605-2 is engaged with the driving gear 605-1 in the tertiary platform panel driving module 605 on the lower side of the deployable platform 602, the electromagnetic clutch assembly in the driving device on the lower side of the deployable platform 602 is attracted, the electromagnetic clutch assembly in the driving device on the lower side of the secondary platform panel 404-4 is disconnected, realizing the alternate transmission relationship of the driving device; finally, under the driving of the first step motor 605-3 in the driving device on the lower side of the deployable platform 602, the tertiary platform panel 604 reaches the lower side of the deployable platform 602 and contacts the second limiting mechanism 606-4; in particular, during the above movement of the tertiary platform panel 604, the coplanarity of the secondary platform panel 404-4 and the deployable platform 602 needs to be strictly controlled, so as to ensure the alignment of the third guide rail 606-1 and the fourth guide rail 606-3 on the lower side of the two.

[0154] As Figure 9 , Figure 11As shown, the facade welding auxiliary module 6 of the embodiment includes four sets of tertiary platform panel limiting devices 607, which include a second stepper motor 607-1, a gear 607-2, a fifth guide groove 607-3, a sliding limiting assembly 607-4, a rack 607-5, and a baffle 607-6, wherein: the fifth guide groove 607-3 is respectively installed at the edges of the secondary platform panel 404-4 and the expandable platform 602, the sliding limiting assembly 607-4 sleeved in the fifth guide groove 607-3 passes through the upper and lower surfaces of the secondary platform panel 404-4 and the expandable platform 602, and the specific installation position is as shown in Figure 9 As shown, the second stepper motor 607-1 is installed at the side of the fifth guide groove 607-3, the output shaft of the second stepper motor 607-1 is connected with the gear 607-2 through the reserved hole of the fifth guide groove 607-3, the sliding limiting assembly 607-4 is slidingly installed inside the fifth guide groove 607-3, the gear 607-2 is engaged with the rack 607-5 installed inside the sliding limiting assembly 607-4, the baffle 607-6 is machined at the lower side of the sliding limiting assembly 607-4, the width of the baffle 607-6 is greater than that of the sliding limiting assembly 607-4, and the lower end of the baffle 607-6 is machined with a bevel, which can better limit the position of the tertiary platform panel 604 and facilitate locking; the third laser ranging sensor 1007 is respectively installed at one side of the lower surface of the secondary platform panel 404-4 and the expandable platform 602 to monitor the displacement of the tertiary platform panel 604.

[0155] Further, taking the process of the tertiary platform panel 604 from the lower side of the secondary platform panel 404-4 to the lower side of the expandable platform 602 as an example, the limiting process of the tertiary platform panel limiting device 607 is described.

[0156] When the tertiary platform panel 604 is located at the lower side of the secondary platform panel 404-4, the gear 607-2 installed on the output shaft of the second stepper motor 607-1 in the tertiary platform panel limiting device 607 installed at one side of the secondary platform panel 404-4 drives the rack 607-5 inside the sliding limiting assembly 607-4 to move, realizing the descent of the baffle 607-6 at the lower side of the sliding limiting assembly 607-4, and then the baffle 607-6 and the first limiting assembly 606-2 jointly complete the limiting of the two side surfaces of the tertiary platform panel 604.

[0157] Further, when the tertiary platform panel 604 needs to enter the lower side of the expandable platform 602, first, the baffle 607-6 in the tertiary platform panel limiting device 607 installed on the secondary platform panel 404-4 rises to release the tertiary platform panel 604; finally, when the tertiary platform panel 604 enters the lower side of the expandable platform 602, the descent process of the baffle 607-6 in the tertiary platform panel limiting device 607 is repeated, so that the baffle 607-6 and the second limiting assembly 606-4 constitute the limiting of the tertiary platform panel 604.

[0158] To more clearly illustrate this embodiment, the complete workflow of the exterior facade welding auxiliary module 6 is briefly given:

[0159] Driven by the robot's longitudinal movement module 5, the first-level platform panel 401 in the robot's lateral movement module 4 reaches its lowest point in the vertical direction and locks; driven by the robot's lateral movement module 4, the third-level platform panel 604 reaches the lateral center position of the system frame and locks; at this time, the third guide rail 606-1 and the fourth guide rail 606-3 are aligned; combined with the aforementioned partial workflow: under the alternating transmission of the two sets of third-level platform panel drive modules 605, the third-level platform panel 604 moves from the underside of the second-level platform panel 404-4 to the underside of the deployable platform 602; Specifically, during this process, the secondary platform panel 404-4 and the tertiary platform panel limiting device 607 on the underside of the deployable platform 602 work sequentially to release and lock the tertiary platform panel 604; finally, driven by the second ball screw module 601, the deployable platform 602 and the tertiary platform panel 604 achieve a 90° rotation; during this process, the robot posture adjustment module 7, the robot rotation platform module 8, and the rigid-flexible coupling welding robot module 9 installed on the underside of the tertiary platform panel 604 rotate simultaneously, thereby assisting the subsequent robot device to achieve the welding of the exterior facade.

[0160] like Figure 12 As shown, the robot posture adjustment module 7 in this embodiment is a 3-RPS parallel mechanism, which includes a static platform (i.e., the third-level platform panel 604 in the exterior welding auxiliary module 6), a fourth-level moving platform 701, and three motion chains. Specifically: a second support assembly 702, consisting of three motion chains arranged in an equilateral triangle on the underside of the static platform, forms a revolute joint; the fourth-stage moving platform 701 is an equilateral triangular panel, with a ball joint support assembly 704, consisting of three motion chains, mounted along the equilateral triangle on its upper side, forming a spherical joint; furthermore, a reciprocating electric cylinder 703 is mounted on each of the three motion chains, which can be considered as a driving prismatic joint; therefore, each motion chain has one revolute joint, one prismatic joint, and one spherical joint; in particular, the 3-RPS parallel mechanism has two rotational degrees of freedom and one translational degree of freedom; a second angle sensor module 1008 is mounted on the second support assembly 702, used to measure the rotation angles of the three revolute joints; a fourth laser rangefinder sensor 1009 is mounted on the third-stage platform panel 604, used to monitor the displacement of the fourth-stage moving platform 701.

[0161] In particular, the rigid parallel robot has the advantages of large structural stiffness, high load capacity, high motion precision, simple inverse kinematics solution, etc. The 3-RPS parallel mechanism is selected as the pose adjustment device of the rigid-flexible coupling welding robot module 9, which has the advantages of high motion precision, simple control, and is convenient for subsequent large-scale design of the device.

[0162] As shown in Figure 13 , the robot rotation platform module 8 of the embodiment includes a servo drive motor 801, a static platform (i.e. the four-stage moving platform 701 in the robot pose adjustment module 7), a motor output shaft flange 802, a thrust aligning roller bearing 803, a first thrust bearing support 804, a second thrust bearing support 805, and a five-stage rotation platform 806.

[0163] The servo drive motor 801 is vertically installed on the upper side of the four-stage moving platform 701 by bolts. The output shaft of the servo drive motor 801 passes through the reserved hole of the four-stage moving platform 701 and is installed with the motor output shaft flange 802 at the shaft end. The motor output shaft flange 802 is connected with the five-stage rotation platform 806 by a bolt set. The edge of the first thrust bearing support 804 is processed with a threaded hole. The first thrust bearing support 804 is installed on the four-stage moving platform 701 by screws between the four-stage moving platform 701 and the five-stage rotation platform 806. The thrust aligning roller bearing 803 and the second thrust bearing support 805 are sleeved on the first thrust bearing support 804 from inside to outside. In addition, the upper side outer ring of the first thrust bearing support 804 is connected with the inner ring by threads, which facilitates the installation of the thrust aligning roller bearing 803 and the second thrust bearing support 805. The edge of the second thrust bearing support 805 is processed with a through hole, which is installed on the five-stage rotation platform 806 by a bolt set. In particular, the lower side ring of the first thrust bearing support 804 and the upper side ring of the second thrust bearing support 805 are respectively installed on the bottom surface and the top surface of the thrust aligning roller bearing 803. A third angle sensor 1010 is installed on the upper side of the five-stage rotation platform 806 and connected with the motor output shaft flange 802, which realizes the monitoring of the rotation amount of the five-stage rotation platform 806.

[0164] As shown in Figure 1 , Figure 12 , Figure 13 , the robot pose adjustment module 7 and the robot rotation platform module 8 are sequentially installed on the lower side of the robot transverse movement module 4 in the embodiment. The rigid-flexible coupling welding robot module 9 is connected with the five-stage rotation platform 806 in the robot rotation platform module 8 by a bolt set.

[0165] In the embodiment, a two-stage robot pose adjustment control mechanism is defined, in which: the robot pose adjustment module 7 and the robot rotation platform module 8 are used as the second-stage robot pose adjustment device to realize the fine adjustment of the welding robot posture, i.e. the horizontal roll motion, the pitch motion, the yaw motion, and the vertical lifting.

[0166] As shown in the figure, the rigid-flexible coupling welding robot module 9 of the embodiment comprises a robot static platform 901, a robot dynamic platform 902, a flexible cable drive system module 903, a flexible cable system 904, a radial extension module 905, a variable stiffness tensioning module 906, and a welding torch module 907. Figure 14

[0167] The flexible cable drive system module 903 is installed on the upper surface of the robot static platform 901, above which is the robot rotary platform module 8; the robot dynamic platform 902 is located below the rigid-flexible coupling welding robot module 9, and the robot dynamic platform 902 always remains parallel to the robot static platform 901; the flexible cable system 904 connects the robot static platform 901 and the robot dynamic platform 902 to form a flexible motion branch chain; in particular, the radial extension module 905 and the variable stiffness tensioning module 906 are nested and further installed between the robot static platform 901 and the robot dynamic platform 902 to form a rigid motion branch chain, realizing the adjustment of the radial position of the robot and the regulation of the overall stiffness of the robot; the welding torch module 907 is installed on the lower side of the robot dynamic platform 902 to realize the welding operation.

[0168] As shown in the figure, the robot static platform 901 and the robot dynamic platform 902 are both equilateral triangle structures, and three groups of through holes 901-1 are machined along the equilateral triangle on the robot static platform 901; the robot static platform 901 is connected with the five-stage rotary platform 806 in the robot rotary platform module 8 through three groups of fixed bolt sets 901-2; the flexible cable drive system 903 is arranged between the five-stage rotary platform 806 and the robot static platform 901; three flexible cable hangers 902-1 are machined along the equilateral triangle on the robot dynamic platform 902, and a first hooke joint assembly 902-2 is installed at the center of the upper surface of the robot dynamic platform 902. Figure 14

[0169] As shown in the figure, Figure 14 , Figure 15 The flexible cable drive system module 903 of the embodiment comprises three groups of flexible cable drive systems arranged along the equilateral triangle; each flexible cable drive system comprises a support base 903-1 installed on the robot static platform 901 through a bolt set, a flexible cable drive servo motor 903-2 and a flexible cable drum 903-4 installed on the support base 903-1; in particular, the flexible cable drive servo motor 903-2 and the flexible cable drum 903-4 are connected through a synchronous pulley assembly 903-3; in addition, the flexible cable drum 903-4 comprises two groups of symmetrical spiral lines to wind two parallel flexible cables; therefore, the rotation of the flexible cable drive servo motor 903-2 is transmitted through the synchronous pulley assembly 903-3 to become the rotation of the flexible cable drum 903-4, which in turn drives the parallel flexible cable branch chain to realize contraction and release.

[0170] As​​Figure 16 , Figure 17 As shown, the flexible cable system 904 in this embodiment includes three sets of parallel flexible cable systems arranged along an equilateral triangle; each parallel flexible cable system includes a first guide wheel 904-1 and a first guide wheel support 904-2 installed on the upper side of the robot stationary platform 901, and a second guide wheel 904-3 and a second guide wheel support 904-4 installed on the lower side of the robot stationary platform 901; compared with the first guide wheel support 904-2 being installed on the inner short side of the through hole 901-1 by screws, the second guide wheel support 904-4 is installed on the outer side to avoid friction between the flexible cable and the robot stationary platform 901.

[0171] Since the spirals on both sides of the flexible cable drum 903-4 are arranged symmetrically, the first flexible cable 904-5 wound on one side of the flexible cable drum 903-4 and the second flexible cable 904-6 wound on the other side of the flexible cable drum 903-4 can be contracted and released simultaneously. The first flexible cable 904-5 and the second flexible cable 904-6 extend from the flexible cable drum 903-4, pass through the first guide wheel 904-1 and through the through hole 901-1, pass through the second guide wheel 904-3 and are finally fixed to the two flexible cable rings 902-1 on the robot moving platform 902 respectively. The other two sets of parallel flexible cables are handled in the same way. In particular, the first flexible cable 904-5 is connected to the cable displacement sensor module 1011 before passing through the second guide wheel 904-3 in order to control the rigid-flexible coupling welding robot and monitor its motion.

[0172] like Figure 14 As shown, since the welding torch module 907 is installed on the lower side of the robot moving platform 902, the rigid-flexible coupling welding robot module 9 needs to have sufficient rigidity in order to realize the welding function. In this embodiment, a variable stiffness tensioning module 906 is designed based on multiple sets of spring devices to ensure that the flexible cable system 904 is passively tensioned. In order to realize rapid welding of complex welds and welding of complex weldments, especially cavities and other geometrically limited parts, the welding torch module 907 needs to extend radially. In this embodiment, a radial extension module 905 is designed to realize the radial extension of the robot moving platform 902, realize a large adjustment of the radial position of the welding torch module 907, avoid frequent robot pose changes, and improve welding efficiency.

[0173] like Figure 14 , Figure 17As shown, the radial stretching module 905 of the embodiment includes a second hooke joint assembly 905-1 mounted on the robot static platform 901, a third stepper motor 905-2 mounted on the lower side of the second hooke joint assembly 905-1, a flange 905-3 and a lead screw 905-4. Among them, the flange 905-3 is connected with the lower support of the second hooke joint assembly 905-1 through a plurality of bolts; a second coupling 905-5 is further installed between the flange 905-3 and the lower support of the second hooke joint, one end of the second coupling 905-5 is connected with the output shaft of the third stepper motor 905-2, and the other end is connected with the lead screw 905-4.

[0174] As shown in Figure 17 , Figure 18 , it further includes two fifth guide rails 905-6 and a stop block 905-8, the two ends of the fifth guide rail 905-6 are respectively installed on the flange 905-3 and the stop block 905-8 through screws; a nut block 905-9 and a first sleeve 905-7 are installed on the lead screw 905-4, and the first sleeve 905-7 is connected with the nut block 905-9 through screws; the radial stretching module 905 drives the lead screw 905-4 on which the nut block 905-9 and the first sleeve 905-7 are sleeved to rotate through the third stepper motor 905-2, the nut block 905-9 further converts the rotary motion of the lead screw 905-4 into sliding motion to realize the stretching of the rigid motion branch chain.

[0175] Particularly, as shown in Figure 17 , Figure 18 and Figure 19 , a group of through holes are processed on the flange 905-3, a group of threaded holes are processed on the second sleeve outer ring 906-2 and the second sleeve outer ring 906-3 of the second sleeve 906-1; a plurality of lead screw spring mechanisms (herein eight groups are taken as an example) are installed on the through holes and threaded holes of the flange 905-3, the first sleeve outer ring 906-2 and the second sleeve outer ring 906-3, wherein the bottom of the lead screw spring assembly is fixedly installed on the threaded hole of the second sleeve outer ring 906-3, and the top passes through the through hole on the flange 905-3.

[0176] Specifically, as shown in Figure 19As shown, the screw rod spring mechanism is threaded on a specific stroke of the threaded rod 906-4, and the rest is a smooth rod; the threaded rod 906-4 is sleeved with a spring 906-5, and the threaded part of the threaded rod 906-4 is provided with a double nut 906-6; in particular, the inner and outer rings of the double nut 906-6 are threaded, the inner ring thread is connected with the threaded part of the threaded rod 906-4, and the outer ring part can be connected with the threaded hole on the second sleeve outer ring 906-3; therefore, when the outer ring part of the double nut 906-6 is connected with the threaded hole on the first sleeve outer ring 906-2, the screw rod spring mechanism provides elastic force to the robot system to keep the cable system 904 tensioned; otherwise, when the outer ring part of the double nut 906-6 is disconnected from the threaded hole on the first sleeve outer ring 906-2, the screw rod spring mechanism no longer provides elastic force to the robot system.

[0177] Therefore, by selecting an appropriate number of screw rod spring mechanisms to provide elastic force to the variable stiffness tensioning module 906, the stiffness of the rigid branch of the rigid-flexible coupling welding robot module 9 can be changed.

[0178] In summary, the embodiment designs a rigid-flexible coupling welding robot system, which has omnidirectional autonomous movement capability and significantly expands the operation coverage. The rigid-flexible coupling robot can efficiently process non-standardized welding pieces and complex welds, and supports rapid switching between welding processes. A high-precision pose adjustment device is designed to further expand the working space and improve the overall welding efficiency.

[0179] The embodiment discloses a working method of the movable rigid-flexible coupling welding robot system. Figure 20 As shown, the process is as follows:

[0180] Step 1, system initialization, sensor opening and testing, system calibration and recording of initial signals of each sensor;

[0181] Step 2, omnidirectional movement of the movable base: based on the depth camera 1001 and the laser radar 1002, the robot is positioned and the scene is mapped, the robot system motion trajectory is planned, and the movable base 1 is driven to move omnidirectionally to reach the specified operation position;

[0182] Step 3, multi-view three-dimensional reconstruction: the hydraulic lifting module 2 drives the system frame 3 to vertically lift, the local welding piece point cloud data is acquired by the welding piece scanning visual sensor 1003 driven by the third ball screw module 303, and high-quality welding piece point cloud is acquired by a multi-view three-dimensional reconstruction method (such as an Iterative Closest Point (ICP) algorithm);

[0183] Step 4, for large and complex welding parts, only partial part point cloud information can be obtained by single execution of steps 2 to 3, in order to obtain complete part point cloud, steps 2 to 3 need to be repeatedly executed, and multiple partial part point clouds need to be registered until the part point cloud reconstruction is completed;

[0184] Step 5, according to the geometric characteristics of the welding part, the welding seam generation is carried out in the welding manufacturing system deployed in the cloud;

[0185] Step 6, a plurality of welding seams are grouped and sorted according to the welding seam characteristics, the workpiece geometric shape and the task priority; in particular, the welding seams involving the facade welding are strictly separated from other welding seams, and the welding seams with a length exceeding the working space of the robot system base in the stationary state are strictly separated from other welding seams;

[0186] Step 7: according to whether the welding seam group is a facade welding task, it is determined whether to use the facade welding auxiliary module 6 to drive the three-stage platform panel 604 and the robot pose adjustment module 7, the robot rotating platform module 8 and the rigid-flex coupled welding robot module 9 on the underside thereof to simultaneously flip over by 90°, the specific implementation method has been described in detail in the foregoing;

[0187] Step 8: according to the welding seam characteristics and the welding robot system kinematics, the welding gun trajectory generation is carried out, further, according to the scene map and the welding part point cloud, the hydraulic lifting module 2 drives the system frame 3 to lift to adapt to the part size while avoiding obstacles, preventing the robot system from interfering with the work environment and the welding part;

[0188] Step 9, robot pose adjustment method:

[0189] Firstly, the robot horizontal movement module 4 and the robot longitudinal movement module 5 are used for preliminary adjustment of the robot pose, i.e. horizontal movement, vertical lifting and horizontal roll movement, the purpose of which is to move the welding robot to the vicinity of the welding part while avoiding collision;

[0190] Further, the robot pose adjustment module 7 and the robot rotating platform module 8 are used for fine adjustment of the robot pose, i.e. horizontal roll movement, pitch movement, yaw movement and vertical lifting, the purpose of which is to adjust the welding gun to the starting point position of the welding seam while adjusting the welding gun angle, facilitating the arc striking;

[0191] Step 10, according to the welding gun trajectory, the robot longitudinal movement module 5, the robot horizontal movement module 4, the robot pose adjustment module 7, the robot rotating platform module 8 and the rigid-flex coupled welding robot module 9 cooperate to realize continuous welding operation; in this process, the robot pose adjustment modules cyclically execute adjustment operation to ensure stable and efficient welding;

[0192] Step 11, for the weld length exceeding the working space of the robot system base in the static state, it needs to be repeated in segments:

[0193] i. Step 2 to Step 3;

[0194] ii. Step 8 to Step 10, long weld seam welding is achieved by movable base movement assistance;

[0195] Step 12, repeat Step 8-11 after completing a weld seam, until a group of weld seams are completed;

[0196] Step 13, repeat Step 7-11 after completing a group of weld seams, until all weld seams are completed.

[0197] The present application is not limited to the above embodiments, on the basis of the technical solutions disclosed in the present application, those skilled in the art can make some substitutions and deformations to some technical features according to the disclosed technical content without creative labor, and these substitutions and deformations are within the protection scope of the present application.

Claims

1. A mobile rigid-flexible coupling welding robot system, characterized in that, include: The movable base module (1) includes a frame module (102) and a wheel module (103) that can move omnidirectionally within the welding work scene, and is used to achieve the operation scene coverage of the welding robot system; The hydraulic lifting module (2) includes a hydraulic cylinder (202) and kinematic components mounted on a movable base module (1) for lifting the welding robot system frame. The system framework (3) is installed above the hydraulic lifting module (2) to support the robot lateral movement module (4), the robot longitudinal movement module (5), the exterior welding auxiliary module (6), the robot posture adjustment module (7), the robot rotating platform module (8) and the rigid-flexible coupling welding robot module (9), thus constructing the overall system structure. The rigid-flexible coupling welding robot module (9) is a parallel flexible cable driven welding robot device used to adjust the position and posture of the welding gun module (907) to realize all-round welding of complex weldments. The robot longitudinal movement module (5) includes a ball screw module and kinematic pair components, which are used to adjust the longitudinal position and roll angle of the welding robot device. The robot lateral movement module (4) is a moving platform composed of two-stage guide components and a drive device, used to realize the lateral position adjustment of the welding robot device located below it; The exterior welding auxiliary module (6) is a deployable mechanism that rotates along the outside of the system frame (3). It uses at least two sets of electromagnetic clutch-based drive systems to achieve alternating transmission between the welding robot device along the robot's lateral movement module (4) and the lower side of the deployable mechanism, thereby assisting in the exterior welding operation. The robot posture adjustment module (7) is located below the robot lateral movement module (4). It is a 3-RPS parallel mechanism. By controlling the motion of the three motion chains, the two rotations and one translation of the welding robot device can be adjusted. The robot rotation platform module (8) is located between the robot posture adjustment module (7) and the rigid-flexible coupling welding robot module (9) and is used to adjust the rotation of the rigid-flexible coupling welding robot module (9). The sensor system module (10) is used for positioning the movable base module (1), and for monitoring the motion of the robot lateral movement module (4), robot longitudinal movement module (5), facade welding auxiliary module (6), robot posture adjustment module (7), robot rotating platform module (8) and rigid-flexible coupling welding robot module (9).

2. The mobile rigid-flexible coupling welding robot system according to claim 1, characterized in that, The system frame (3) is a truss structure, which includes four symmetrically installed structural support components (301) and transverse linkage components (302). The movable base module (1) and the hydraulic lifting module (2) are installed on the lower side of the structural support components (301) in sequence. The robot longitudinal movement module (5) is vertically installed in the middle of the structural support components (301), and the robot transverse movement module (4) is located in the middle of the system frame (3) and installed on the lower side of the robot longitudinal movement module (5). The exterior welding auxiliary module (6) is hinged to the side of the structural support components (301) and connected to the transverse linkage components (302) through a linkage.

3. The mobile rigid-flexible coupling welding robot system according to claim 1, characterized in that, The robot's lateral movement module (4) includes a primary platform panel (401) that connects to the ball screw module in the robot's longitudinal movement module (5). Below the primary platform panel (401) are a lateral movement module drive assembly (403) and a lateral movement module guide assembly (404). The lateral movement module drive assembly (403) is a long-stroke ball screw module, and the lateral movement module guide assembly (404) includes two levels of guide assemblies: The primary guide assembly includes two first guide rails (404-1) and a primary moving platform (404-2). The primary moving platform (404-2) is fixedly mounted on the lead screw nut (403-4) of the lateral moving module drive assembly (403). The secondary guide assembly includes two second guide rails (404-3) located outside the first guide rail (404-1) and a secondary platform panel (404-4). The secondary platform panel (404-4) is connected to the second guide rail (404-3) via the second guide rail slider (404-5) and is connected to the lower surface of the primary moving platform (404-2) to drive the secondary platform panel (404-4).

4. The mobile rigid-flexible coupling welding robot system according to claim 1, characterized in that, The exterior welding auxiliary module (6) includes a second ball screw module (601) mounted on the transverse link assembly (302) of the system frame (3), and a connecting rod (603) hinged to the slider of the second ball screw module (601). The connecting rod (603) is hinged to the deployable platform (602). The deployable platform (602) is hinged to the front side of the structural support assembly (301) via a pivot (608). Driven by the second ball screw module (601), the deployable platform (602) can rotate around the pivot (608).

5. A mobile rigid-flexible coupling welding robot system according to claim 4, characterized in that, Two sets of tertiary platform panel drive modules (605) and two sets of tertiary platform panel guide modules (606) are provided on the lower surface of the secondary platform panel (404-4) of the deployable platform (602) and the robot lateral movement module (4). The tertiary platform panel (604) is connected to the guide rail slider of the tertiary platform panel guide module (606) and moves linearly with a single degree of freedom along the lower surface of the deployable platform (602) and the secondary platform panel (404-4). The three-stage platform panel drive module (605) is connected to the drive gear (605-1) via the first stepper motor (605-3) to mesh with the driven rack (605-2) on the three-stage platform panel (604). The electromagnetic clutch assembly between the output shaft of the first stepper motor (605-3) and the drive gear (605-1) is engaged or disengaged to realize the alternating meshing of the driven rack (605-2) with the drive gears (605-1) of the two sets of drive devices for motion transmission.

6. A mobile rigid-flexible coupling welding robot system according to claim 4, characterized in that, The exterior welding auxiliary module (6) also includes at least four sets of three-level platform panel limiting devices (607). The three-level platform panel limiting devices (607) include a second-level platform panel (404-4) installed on the robot's lateral movement module (4) and a fifth guide groove (607-3) installed on the edge of the unfoldable platform (602). A second stepper motor (607-1) is fixedly connected to the fifth guide groove (607-3). The second stepper motor (607-1) drives the gear (607-2) to mesh with the rack (607-5) inside the sliding limiting component (607-4), thereby driving the sliding limiting component (607-4) with the baffle (607-6) to move up and down along the fifth guide groove (607-3) to limit the three-level platform panel (604).

7. A mobile rigid-flexible coupling welding robot system according to claim 1, characterized in that, The robot posture adjustment module (7) includes three motion branches and their motion pairs that connect to the three-level platform panel (604) of the exterior welding auxiliary module (6). A reversing electric cylinder (703) is installed on each of the three motion branches to form a drive moving pair. The three motion branches are connected to the four-level moving platform (701), which is connected to the robot rotation platform module (8). The robot posture adjustment module (7) has two rotational degrees of freedom and one translational degree of freedom.

8. A mobile rigid-flexible coupling welding robot system according to claim 1, characterized in that, The robot rotating platform module (8) includes a servo drive motor (801) connected to the four-stage moving platform (701) of the robot posture adjustment module (7). The output shaft of the servo drive motor (801) is connected to the motor output shaft flange (802). The motor output shaft flange (802) passes through the thrust self-aligning roller bearing (803) and is connected to the five-stage rotating platform (806). The robot rotating platform module (8) has one rotational degree of freedom.

9. A mobile rigid-flexible coupling welding robot system according to claim 1, characterized in that, The rigid-flexible coupling welding robot module (9) includes a robot stationary platform (901) located below the five-stage rotating platform (806) of the robot rotating platform module (8), and a robot moving platform (902) parallel to the robot stationary platform (901). A flexible cable system (904) is connected between the robot stationary platform (901) and the robot moving platform (902) to form a flexible motion branch. Nested radial extension modules (905) and variable stiffness tensioning modules (906) are provided between the robot stationary platform (901) and the robot moving platform (902) to form a rigid motion branch. A welding torch module (907) is connected to the lower side of the robot moving platform (902). Each flexible cable system (904) drives the flexible cable drum (903-4) to rotate via the flexible cable drive servo motor (903-2), thereby driving the parallel flexible cable branches that bypass the flexible cable drum (903-4) to achieve contraction and release; The radial extension module (905) drives the lead screw (905-4) with the nut slider (905-9) and the first sleeve (905-7) to rotate through the third stepper motor (905-2), thereby realizing the extension of the rigid motion chain; The variable stiffness tensioning module (906) achieves tensioning of the flexible cable connected to the robot moving platform (902) and robot stationary platform (901) at the bottom of the variable stiffness tensioning module (906) by extending and retracting the screw spring mechanism connected below the radial extension module (905), and adjusts the stiffness of the rigid motion branch by controlling the number of springs connected to the screw spring mechanism.

10. A welding method for a mobile rigid-flexible coupling welding robot according to any one of claims 1-9, characterized in that, include: S1, Welding robot system initialization, sensor system module (10) testing, system calibration; S2, the movable base module (1) performs robot positioning and scene mapping based on the sensor system module (10) and plans the motion trajectory of the welding robot system; S3, the hydraulic lifting module (2) drives the system frame (3) to lift vertically, and the sensor system module (10) on the system frame (3) obtains local weldment point cloud data, and obtains high-quality weldment point cloud through multi-view three-dimensional reconstruction method; S4. For large and complex welded parts, repeat steps S2-S3 to register multiple local welded part point clouds until the welded part point cloud reconstruction is completed. S5 generates welds in a cloud-based welding manufacturing system based on the geometric features of the weldment. S6, group and sort multiple welds according to weld characteristics, workpiece geometry and task priority; separate welds involving exterior facade welding from other welds, and separate welds whose length exceeds the working space of the movable base module (1) of the welding robot system in a static state from other welds. S7. Depending on whether the weld group is an exterior welding task, determine whether to use the exterior welding auxiliary module (6) to drive the three-level platform panel (604) and its lower robot posture adjustment module (7), robot rotation platform module (8) and rigid-flexible coupling welding robot module (9) to rotate 90°. S8, based on the weld seam characteristics and the motion of the welding robot system, the welding gun trajectory is generated. Combined with the scene map and the point cloud of the welded parts, the hydraulic lifting module (2) drives the system frame (3) to lift and achieve obstacle avoidance. S9, use the robot longitudinal movement module (5) and the robot lateral movement module (4) to perform preliminary pose adjustment of the robot's vertical lifting, horizontal movement and rolling motion; The robot pose adjustment module (7) and the robot rotation platform module (8) are used to finely adjust the robot's pose, including roll, pitch, yaw and vertical lifting. S10, according to the welding torch trajectory, the robot longitudinal movement module (5), the robot lateral movement module (4), the robot posture adjustment module (7), the robot rotating platform module (8) and the rigid-flexible coupling welding robot module (9) work together to perform continuous welding operations; the robot posture adjustment module (7) and the robot rotating platform module (8) perform posture adjustment in a cyclic manner; S11, for welds whose length exceeds the working space of the welding robot system base when stationary, the process needs to be repeated in segments: i. Steps S2-S3; ii. Steps S8-S10, long weld seam welding is achieved with motion assistance from the movable base module (1); S12, after each weld is completed, repeat steps S8-S11 until a set of welds is completed; S13. After each set of welds is completed, repeat steps S7-S11 until all welds are completed.

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