A three-branch, six-DOF mobile parallel composite robot

Abstract

A three-branch, six-DOF (degrees of freedom) parallel composite robot includes a carrier body that moves with a planar mobile platform. The carrier body is equipped with a six-DOF attitude adjustment mechanism and an electronic control module. A moving platform module is mounted on top of the six-DOF attitude adjustment mechanism. The six-DOF attitude adjustment mechanism includes three branches, each branch comprising a lateral sliding joint and a vertical sliding joint connected by a cross-slider. The lateral sliding joint is mounted on a first mounting plate and driven by a first lead screw, while the vertical sliding joint is mounted on a second mounting plate and driven by a second lead screw. The second mounting plate is connected to the moving platform module via a ball joint. When the planar mobile platform is locked, the six-DOF attitude adjustment mechanism achieves six-DOF pose adjustment of the moving platform module through the coordinated movement of the lateral and vertical sliding joints of the three branches. This invention features high load capacity, high rigidity, and a large extension ratio, maintaining overall stability while balancing flexibility and workspace.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, specifically relating to a three-branch, six-degree-of-freedom mobile parallel composite robot. Background Technology

[0002] Currently, with the rapid development of aerospace, energy equipment, and large-scale machinery manufacturing, the level of large-scale equipment development has become an important indicator of manufacturing capability. Among these, the assembly of large components is a key link affecting the overall development quality and efficiency. In existing technologies, most companies still rely primarily on hand-cranked brackets or hoisting equipment for large component assembly. This type of assembly method has shortcomings in terms of spatial orientation adjustment freedom and precision, the assembly process is highly dependent on human experience, and it has poor compatibility with multiple product models, making it difficult to meet the demands for efficient assembly. Large components are generally characterized by their large size and heavy weight. Conventional mobile assembly equipment has certain limitations in terms of load-bearing capacity, structural rigidity, and motion performance. On the one hand, its load-bearing capacity is insufficient to meet the requirements for handling and adjusting heavy components; on the other hand, its structural rigidity is low, making it prone to deformation during operation and affecting assembly accuracy; furthermore, some equipment has limited extension ratios and poor adaptability, making it difficult to cover various working conditions. To meet the requirements of efficient, precise, and flexible assembly of large components, designing an autonomous mobile robot with high load-bearing capacity, high rigidity, and a large extension ratio is an effective solution.

[0003] Currently, some mobile robots only possess simple grasping or handling functions, making it difficult to meet complex assembly requirements. For example, the robot disclosed in patent CN 214520162U mainly achieves lifting and lateral displacement through lead screws, with limited degrees of freedom, making it unable to complete multi-angle precision docking tasks. Furthermore, many mobile assembly robots suffer from insufficient rigidity due to their serial arm structures. For instance, the serial structure of the first, second, and third arms connected in sequence in patent CN 105500333A, and the integrated multi-joint serial robotic arm disclosed in CN 119589634A, have open chain structures that are prone to deformation under heavy loads, exhibiting poor rigidity and failing to meet the high precision and stability requirements for assembling large components. Moreover, some six-degree-of-freedom mobile assembly robots that use a six-degree-of-freedom attitude adjustment mechanism also have design flaws. For example, the solution in patent CN104802151A places the parallel platform on top of the lifting mechanism and then installs it on the mobile platform as a whole. This vertically stacked structure results in an excessively high center of gravity for the entire machine, which leads to poor stability when carrying large-sized and heavy workpieces, making it unsuitable for mobile assembly and difficult to apply to narrow spaces with height restrictions.

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an autonomous mobile robot with high load capacity, high rigidity, and a large extension ratio. Summary of the Invention

[0005] This invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a three-branch, six-degree-of-freedom mobile parallel composite robot.

[0006] The technical solution of this invention is: A three-branch six-degree-of-freedom mobile parallel composite robot includes a carrier body that moves with a planar mobile platform, on which a six-degree-of-freedom attitude adjustment mechanism and an electronic control module are installed. The top of the six-degree-of-freedom attitude adjustment mechanism is provided with a moving platform module. The six-degree-of-freedom attitude adjustment mechanism includes a first branch, a second branch, and a third branch. The first branch is located on the front side of the frame, and the second and third branches are located on the left and right sides of the frame, respectively. Each branch includes a lateral sliding joint and a vertical sliding joint connected by a cross slider. The lateral sliding joint is mounted on a first mounting plate fixedly connected to the frame and driven by a first lead screw. The vertical sliding joint is mounted on a second mounting plate and driven by a second lead screw. The second mounting plate is connected to the moving platform module through a ball joint. The ball joint includes a second ball joint seat disposed on the second mounting plate and a first ball joint seat disposed on the moving platform module. The second ball joint seat is provided with an inner ball and a ball joint ball bearing. The first ball joint seat is connected to the second ball joint seat by bolts and rotates with the inner ball of the ball joint. The planar moving platform has a locked state. When in the locked state, the six-degree-of-freedom attitude adjustment mechanism realizes the six-degree-of-freedom attitude adjustment of the moving platform module through the coordinated movement of the lateral and vertical lateral joints of the three branches.

[0007] Furthermore, the cross slider includes a first cross shaft and a second cross shaft. The end face of the first cross shaft is provided with a first slider that is connected to the first lead screw groove, and the end face of the second cross shaft is provided with a second slider that is connected to the second lead screw groove. The first cross shaft and the second cross shaft are movably connected by a connecting shaft.

[0008] Furthermore, the slots of the first slider and the second slider are spatially perpendicular to each other.

[0009] Furthermore, the two ends of the connecting shaft are mounted on bearings, the bearings are mounted on the first cross shaft, and bearing end caps are mounted on both ends of the bearings, which are fixed to the first cross shaft by bolts.

[0010] Furthermore, the lateral movement pair also includes a first guide rail seat, a second guide rail seat, and a first guide rail module that are fixed to the first mounting plate by bolts. The first guide rail seat and the second guide rail seat are fixed to the two ends of the first lead screw, respectively. The branch first servo motor is fixed to the first mounting plate by bolts, and the first lead screw and the branch first servo motor are connected by a first synchronous belt module.

[0011] Furthermore, the vertical moving pair also includes a third guide rail seat, a fourth guide rail seat, and a second guide rail module that are fixed to the second mounting plate by bolts. The second lead screw is fixed to the third guide rail seat and the fourth guide rail seat at both ends, respectively. The branch second servo motor is fixed to the second servo motor bracket by bolts. The second servo motor bracket is fixed to the second mounting plate by bolts. The second lead screw and the branch second servo motor are connected through a second synchronous belt module.

[0012] Furthermore, the planar moving platform includes a first drive wheel set, a second drive wheel set, a third drive wheel set, and a fourth drive wheel set bolted to the bottom of the frame. Each drive wheel set includes a Mecanum wheel independently driven by a wheel set servo motor.

[0013] Furthermore, the output end of the wheel set servo motor is connected to a planetary reducer, and the output end of the planetary reducer drives the Mecanum wheel through a transmission seat.

[0014] Furthermore, the transmission seat is installed in the wheel set bracket, and a shock-absorbing module for shock absorption is provided between the transmission seat and the wheel set bracket.

[0015] The beneficial effects of this invention are as follows: 1. The parallel three-chain structure is adopted, and all three chains are directly connected to the frame and the moving platform. This fundamentally avoids the stress state of a cantilever beam, so that when the mechanism carries large components, the load is distributed among the three chains, which greatly improves the rigidity of the overall structure and ensures that high-load and high-rigidity assembly operations can still be achieved under heavy load conditions.

[0016] 2. The drive components of the six-degree-of-freedom attitude adjustment mechanism are all arranged at the bottom of the frame or near the frame. This layout significantly lowers the center of gravity of the whole machine. When carrying large-sized and heavy workpieces and making rapid planar movements, it can effectively suppress the risk of swaying and tipping, and improve the safety and reliability of the robot in dynamic operations.

[0017] 3. The three-chain parallel structure and the low center of gravity layout of the drive components reduce the overall height of the robot, allowing it to easily enter confined spaces with height restrictions, such as hangars and ship cabins, to carry out operations. This broadens its application scenarios and solves the problem that traditional high center of gravity equipment cannot adapt to low-lying environments.

[0018] In summary, this invention has the advantages of high load capacity, high rigidity and large extension ratio. While maintaining the stability of the whole machine, it also takes into account flexibility and working space, which can meet the application requirements of large structural components in the assembly, transportation and attitude adjustment process. It is particularly suitable for high-precision assembly tasks in the fields of aerospace, energy equipment and large machinery manufacturing. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the entire machine without a casing; Figure 3 This is a structural schematic diagram of the motionless platform module of the present invention; Figure 4 This is a schematic diagram of the moving platform module of the present invention; Figure 5 This is a schematic diagram of the drive wheel assembly of the present invention; Figure 6 This is a front view schematic diagram of the branch of the six-degree-of-freedom attitude adjustment mechanism of the present invention; Figure 7 This is a rear view schematic diagram of the branch of the six-degree-of-freedom attitude adjustment mechanism of the present invention; Figure 8 This is a schematic diagram of the cross slider of the six-degree-of-freedom attitude adjustment mechanism of the present invention; in: 1. Housing 2. Emergency stop switch 3. Start / Stop Switch 4. Planar Moving Platform 5. Six-degree-of-freedom attitude adjustment mechanism; 6. Chassis. 7. Dynamic platform module 8. First drive wheel set 9 First branch chain 10 Second drive wheel assembly 11 Second branch chain 12 Third drive wheel assembly 13 Fourth drive wheel assembly 14 Third branch chain 15 Servo motor driver 16 Six-DOF attitude adjustment mechanism control module 17 Central Processing Unit 18 Mobile Platform Control Module 19 Battery Module 20 Motion Platform Frame 21 First ball joint seat 22 Moving platform skin 23 Wheelset servo motor 24 Planetary reducer 25 Shock Absorption Module 26 Wheelset Bracket 27 Mecanum Wheel 28 First Mounting Plate 29 First guide rail seat 30 First lead screw 31 First guide rail module 32 Cross slider 33 Second mounting plate 34 Branch first servo motor 35 First synchronous belt module 36 Second guide rail base 37 Second servo motor of branch chain 38 Second servo motor bracket 39. Ball joint inner ball bearing; 40. Ball joint ball bearing 41 Second ball joint seat 42 Second synchronous belt module 43 Third guide rail seat 44 Second lead screw 45 Second guide rail module 46 Fourth guide rail base 47 First cross axis 48 First slider 49 First nut 50 Bearing 51 Connecting shaft 52 Second cross shaft 53 Second slider 54 Second nut 55 Bearing end cap. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments: Example

[0021] like Figures 1 to 8 As shown, a three-branch, six-DOF (degrees of freedom) mobile parallel composite robot includes a carrier vehicle that moves with a planar mobile platform 4. A six-DOF attitude adjustment mechanism 5 and an electronic control module are mounted on the carrier vehicle. A motion platform module 7 for outputting spatial position and attitude is located on the top of the six-DOF attitude adjustment mechanism 5. The planar mobile platform 4 is used to achieve large-scale overall movement and transfer. The six-DOF attitude adjustment mechanism 5 is used to achieve precise attitude adjustment and spatial positioning of components. The electronic control module is used to drive and control the movement of the planar mobile platform 4 and the six-DOF attitude adjustment mechanism 5. The six-degree-of-freedom attitude adjustment mechanism 5 includes a first branch 9, a second branch 11 and a third branch 14. The first branch 9 is located on the front side of the frame 6, and the second branch 11 and the third branch 14 are located on the left and right sides of the frame 6, respectively. Each branch includes a lateral sliding joint and a vertical sliding joint connected by a cross slider 32. The first mounting plate 28 is fixedly connected to the frame 6. The lateral sliding joint is set on the first mounting plate 28 and driven by the first lead screw 30. The vertical sliding joint is set on the second mounting plate 33 and driven by the second lead screw 44. The second mounting plate 33 is connected to the moving platform module 7 through a ball joint. The planar moving platform 4 has a locked state. When it is in the locked state, the six-degree-of-freedom attitude adjustment mechanism 5 realizes the six-degree-of-freedom attitude adjustment of the moving platform module 7 through the coordinated movement of the lateral and vertical moving joints of the three branches.

[0022] Furthermore, the cross slider 32 includes a first cross shaft 47 and a second cross shaft 52. The end face of the first cross shaft 47 is provided with a first slider 48 connected to the slot of the first lead screw 30. The end face of the second cross shaft 52 is provided with a second slider 53 connected to the slot of the second lead screw 44. The first cross shaft 47 and the second cross shaft 52 are movably connected by a connecting shaft 51.

[0023] Furthermore, the slots of the first slider 48 and the second slider 53 are spatially perpendicular to each other.

[0024] Furthermore, the two ends of the connecting shaft 51 are mounted on bearings 50, the bearings 50 are mounted on the first cross shaft 47, and bearing end caps 55 are mounted on both ends of the bearings 50. The bearing end caps 55 are fixed to the first cross shaft 47 by bolts.

[0025] Furthermore, the ball joint includes a second ball joint seat 41 disposed on the second mounting plate 33 and a first ball joint seat 21 disposed on the moving platform module 7. The second ball joint seat 41 is provided with a ball joint inner ball 39 and a ball joint ball bearing 40. The first ball joint seat 21 is connected to the second ball joint seat 41 by bolts and cooperates with the ball joint inner ball 39 to form a rotatable connection.

[0026] Furthermore, the lateral movement pair also includes a first guide rail seat 29, a second guide rail seat 36, and a first guide rail module 31, which are fixed to the first mounting plate 28 by bolts. The first guide rail seat 29 and the second guide rail seat 36 are fixed to the two ends of the first lead screw 30, respectively. The branch first servo motor 34 is fixed to the first mounting plate 28 by bolts, and the first lead screw 30 and the branch first servo motor 34 are connected by a first synchronous belt module 35.

[0027] Furthermore, the vertical moving pair also includes a third guide rail seat 43, a fourth guide rail seat 46, and a second guide rail module 45, which are fixed to the second mounting plate 33 by bolts. The second lead screw 44 has the third guide rail seat 43 and the fourth guide rail seat 46 fixed to its two ends respectively. The branch second servo motor 37 is fixed to the second servo motor bracket 38 by bolts. The second servo motor bracket 38 is fixed to the second mounting plate 33 by bolts. The second lead screw 44 and the branch second servo motor 37 are connected through the second synchronous belt module 42.

[0028] Furthermore, the planar moving platform 4 includes a first drive wheel set 8, a second drive wheel set 10, a third drive wheel set 12 and a fourth drive wheel set 13 bolted to the bottom of the frame 6. Each drive wheel set includes a Mecanum wheel 27 independently driven by a wheel set servo motor 23.

[0029] Furthermore, the output end of the wheel set servo motor 23 is connected to the planetary reducer 24, and the output end of the planetary reducer 24 drives the Mecanum wheel 27 through the transmission seat.

[0030] Furthermore, the transmission seat is installed in the wheel set bracket 26, and a shock-absorbing module 25 for shock absorption is provided between the transmission seat and the wheel set bracket 26.

[0031] Furthermore, the moving platform module 7 also includes a moving platform frame 20, a first ball joint seat 21, and a moving platform skin 22.

[0032] Specifically, the electronic control module includes a servo motor driver 15, a six-degree-of-freedom attitude adjustment mechanism control module 16, a central processing unit 17, a mobile platform control module 18, and a battery module 19. Each module is fixed inside the planar mobile platform 4 by bolts.

[0033] The following describes Embodiment 1 in detail with reference to the accompanying drawings: like Figure 1 As shown, Figure 1 This is a schematic diagram of the overall structure of the present invention. The overall structure includes a housing 1, an emergency stop switch 2, a start / stop switch 3, a planar moving platform 4, and a six-degree-of-freedom attitude adjustment mechanism 5.

[0034] Specifically, the outer shell 1 is used to cover the planar mobile platform 4, the emergency stop switch 2 is used to stop the robot's operation in case of emergencies, and the start / stop switch 3 is used to turn the robot on and off.

[0035] like Figure 2 As shown, Figure 2 This is a structural schematic diagram of the entire device of the present invention without a casing. Figure 1 Based on this, without an outer shell, the planar mobile platform 4 includes a load-bearing frame 6 for large-stroke movement and a drive wheel set, and the mobile platform module 7 is used to realize end-space movement.

[0036] Specifically, the supporting frame 6 is achieved by welding square tubes and provides an installation base for the drive wheel assembly. The planar moving platform 4 provides an installation base for the six-degree-of-freedom attitude adjustment mechanism 5, and the six-degree-of-freedom attitude adjustment mechanism 5 provides an installation base for the moving platform module 7.

[0037] like Figure 3 As shown, Figure 3This is a schematic diagram of the structure of the motionless platform module of the present invention. The drive wheel group of the planar moving platform 4 includes a first drive wheel group 8, a second drive wheel group 10, a third drive wheel group 12, and a fourth drive wheel group 13. The branches of the six-degree-of-freedom attitude adjustment mechanism 5 include a first branch 9, a second branch 11, and a third branch 14. The electronic control module includes a servo motor driver 15, a six-degree-of-freedom attitude adjustment mechanism control module 16, a central processing unit 17, a moving platform control module 18, and a battery module 19.

[0038] Specifically, the drive wheel assembly is bolted to the bottom of the frame 6, the six-degree-of-freedom attitude adjustment mechanism 5 is mounted on the side of the frame 6, and the electronic control module is mounted inside the frame 6.

[0039] In one implementation, the central processing unit 17 provides motion planning instructions to the six-degree-of-freedom attitude adjustment mechanism control module 16 and the mobile platform control module 18. The six-degree-of-freedom attitude adjustment mechanism control module 16 provides motion instructions to the six-degree-of-freedom attitude adjustment mechanism 5 branches, and the mobile platform control module 18 provides motion instructions to the planar mobile platform 4 drive wheel set.

[0040] In one implementation, the servo motor driver 15 is used to receive commands from the mobile platform control module 18 and convert the commands into drive signals for the drive wheel set of the planar mobile platform 4.

[0041] like Figure 4 As shown, Figure 4 This is a schematic diagram of the moving platform module of the present invention. The moving platform module 7 includes a moving platform frame 20, a first ball joint seat 21, and a moving platform skin 22 covering the outside of the moving platform frame 20.

[0042] Specifically, the moving platform frame 20 is achieved by welding square tubes, and the moving platform frame 20, the first ball joint seat 21, and the moving platform skin 22 are connected by welding.

[0043] Specifically, the first ball joint seat 21 is connected to the second ball joint seat 41 by bolts to realize the rotatable connection between the moving platform module 7 and the support chain.

[0044] like Figure 5 As shown, Figure 5 This is a schematic diagram of the drive wheel assembly of the present invention. The drive wheel assembly includes a wheel assembly servo motor 23, a planetary reducer 24, a shock absorption module 25, a wheel assembly bracket 26, and a Mecanum wheel 27.

[0045] Specifically, the wheel set servo motor 23 is bolted to the planetary reducer 24, the planetary reducer 24 is bolted to the shock absorption module 25, the shock absorption module 25 is bolted to the wheel set bracket 26, the wheel set bracket 26 is bolted to the Mecanum wheel 27, and the wheel set bracket 26 is bolted to the frame 6.

[0046] In one implementation, the wheel servo motor 23 is used to provide power for the planar moving platform 4 during the transfer process, the planetary reducer 24 is used to amplify the torque of the wheel servo motor 23, and the shock absorption module 25 is used for buffering and shock absorption during the transfer process of the planar moving platform 4.

[0047] In one implementation, the drive wheel set is used to realize omnidirectional motion during the movement of the planar moving platform 4.

[0048] like Figure 6 and Figure 7 As shown, Figure 6 This is a front view schematic diagram of the branch of the six-degree-of-freedom attitude adjustment mechanism of the present invention. Figure 7 This is a rear view schematic diagram of the six-degree-of-freedom attitude adjustment mechanism support chain of the present invention. The support chain includes a first mounting plate 28, a first guide rail seat 29, a first lead screw 30, a first guide rail module 31, a cross slider 32, a second mounting plate 33, a support chain first servo motor 34, a first synchronous belt module 35, a second guide rail seat 36, a support chain second servo motor 37, a second servo motor bracket 38, a ball joint inner ball 39, a ball joint ball bearing 40, a second ball joint seat 41, a second synchronous belt module 42, a third guide rail seat 43, a second lead screw 44, a second guide rail module 45, and a fourth guide rail seat 46.

[0049] Specifically, the first mounting plate 28 is connected to the frame 6 by welding. The first guide rail seat 29, the first guide rail module 31, the branch first servo motor 34, and the second guide rail seat 36 are all connected to the first mounting plate 28 by bolts. The first lead screw 30 is installed at both ends on the first guide rail seat 29 and the second guide rail seat 36.

[0050] Specifically, the second servo motor bracket 38, the inner ball of the ball joint 39, the ball joint ball bearing 40, the second ball joint seat 41, the second synchronous belt module 42, the third guide rail seat 43, the second lead screw 44, the second guide rail module 45, and the fourth guide rail seat 46 are all connected to the second mounting plate 33 by bolts. The second servo motor 37 is connected to the second servo motor bracket 38 by bolts. The two ends of the second lead screw 44 are installed on the third guide rail seat 43 and the fourth guide rail seat 46.

[0051] Specifically, the cross slider 32 is used to connect the first lead screw 30 and the second lead screw 44.

[0052] Specifically, the first synchronous belt module 35 is used to connect the first servo motor 34 and the first lead screw 30, and the second synchronous belt module 42 is used to connect the second servo motor 37 and the second lead screw 44.

[0053] In one implementation, the branch first servo motor 34 is used to provide power during the rotation of the first lead screw 30, and the branch second servo motor 37 is used to provide power during the rotation of the second lead screw 44.

[0054] In one implementation, the first synchronous belt module 35 is used to support the motion transmission between the first servo motor 34 and the first lead screw 30, and the second synchronous belt module 42 is used to support the motion transmission between the second servo motor 37 and the second lead screw 44.

[0055] In one implementation, the first lead screw 30 and the second lead screw 44 provide active linear translation. The translational movements between the two lead screws are independent of each other and are driven by the first branch servo motor 34 and the second branch servo motor 37, respectively. The cross slider 32 connects the first lead screw 30 and the second lead screw 44 and provides a passive rotational degree of freedom to release constraints when the mechanism deflects, thereby allowing relative angular deflection between the two lead screws, which in turn drives the second mounting plate 33 to rotate around the connecting shaft 51.

[0056] A ball joint is mounted on the second mounting plate 33 to provide three passive rotational degrees of freedom. The first lead screw 30, the second lead screw 44, the cross slider 32, and the ball joint together realize the chain motion. When the moving platform module 7 needs to rotate around the Z-axis, the second mounting plates 33 of the left and right chains generate different X-direction displacements under the guidance of the cross slider 32, causing the moving platform frame 20 to deflect around the Z-axis. During this process, angle compensation and over-constraint elimination during chain deflection are achieved through the cooperation of the ball joint and the cross slider, ensuring smooth movement. Although the first mounting plate 28 of the front chain is fixed, its second mounting plate 33 can still achieve Y-direction displacement through the cross slider 32, which, together with the movement of the left and right chains, realizes the six-degree-of-freedom adjustment of the moving platform module 7.

[0057] like Figure 8 As shown, Figure 8 This is a schematic diagram of the cross slider of the six-degree-of-freedom attitude adjustment mechanism of the present invention. The cross slider 32 is composed of a first cross shaft 47, a first slider 48, a first nut 49, a bearing 50, a connecting shaft 51, a second cross shaft 52, a second slider 53, a second nut 54, and a bearing end cap 55.

[0058] Specifically, the first slider 48 is bolted to the first cross shaft 47, the first slider 48 is connected to the first lead screw 30 through a slot, the first cross shaft 47 is connected to the first lead screw 30 through the first nut 49, and the first slider 48 guides the lateral translation; the second slider 53 is bolted to the second cross shaft 52, the second slider 53 is connected to the second lead screw 44 through a slot, the second cross shaft 52 is connected to the second lead screw 44 through the second nut 54, and the second slider 53 guides the longitudinal translation; the first cross shaft 47 and the second cross shaft 52 are connected by a connecting shaft 51.

[0059] Specifically, the two ends of the connecting shaft 51 are mounted on the bearings 50, the bearings 50 are mounted on the first cross shaft 47, and the two ends of the bearings 50 are mounted with bearing end caps 55, which are fixed to the first cross shaft 47 by bolts.

[0060] This invention adopts a composite form of a planar moving platform and a three-branch six-degree-of-freedom attitude adjustment mechanism welded to the side, which has significant advantages such as large load capacity, high rigidity, high-precision attitude adjustment and high extension ratio.

[0061] Specifically, the high load capacity is mainly achieved by directly welding the six-degree-of-freedom attitude adjustment mechanism 5 to the side of the planar moving platform 4. This fastening connection method ensures a reliable force transmission path and avoids the joint loosening or deformation problems that are prone to occur when the tandem arm is under heavy load. It can effectively carry large-size and heavy-weight workpieces, and supports omnidirectional movement and large-range transfer through four drive wheel sets driven by Mecanum wheels 27.

[0062] High rigidity is achieved through the reinforced design of the cross slider 32, namely, the first cross shaft 47 and the second cross shaft 52 are connected by the connecting shaft 51 and the bearing 50 to form a stable cross structure. At the same time, the lead screw and guide rail module in the branch chain are precisely matched. The above closed chain structure has a greater resistance to deformation than the open chain of the serial arm, maintaining the stability of the system during posture adjustment and avoiding accuracy loss.

[0063] High-precision attitude adjustment benefits from the closed-loop branch design of the six-degree-of-freedom attitude adjustment mechanism. Each branch consists of components such as a servo motor, a synchronous belt module, and a ball joint, realizing six-degree-of-freedom motion of three-way translation and three-way rotation. Combined with the motion planning instructions of the central processing unit 17 and the precise signal conversion of the servo motor driver 15, it ensures micron-level attitude adjustment, which is superior to the cumulative error of the serial arm.

[0064] The high telescoping ratio is achieved by mounting the support chain on the side of the vehicle body, avoiding the problem of an excessively high center of gravity caused by vertical stacking. This allows the system to extend flexibly in confined spaces and adapt to various working conditions. At the same time, the moving platform module 7 further enhances the range of motion and flexibility through the rotatable connection between the ball joint and the support chain.

[0065] This invention achieves large stroke extension through the coupled motion of the double lead screw and cross slider in the branch chain, retaining a large extension ratio, and also has a high-precision six-degree-of-freedom attitude adjustment capability on the basis of large extension.

[0066] Specifically, traditional scissor fork platforms mainly provide vertical lifting, but have limited degrees of freedom and cannot achieve complex spatial positioning. In contrast, the six-degree-of-freedom attitude adjustment mechanism 5 of this invention integrates three branches. Each branch is driven by linear motion through the first lead screw 30 and the second lead screw 44, as well as three degrees of freedom rotation provided by the ball joint. Combined with the output of the moving platform module 7, it can precisely control the spatial position and attitude of the workpiece, making it suitable for high-precision assembly tasks. In addition, this side arrangement lowers the overall center of gravity and improves stability, especially reducing the risk of tipping over during dynamic transportation.

[0067] The present invention adopts a modular design, namely the standardization of branch components and the centralized installation of electronic control modules, including servo motor driver 15, six-degree-of-freedom attitude adjustment mechanism control module 16, central processing unit 17, mobile platform control module 18 and battery module 19, which facilitates manufacturing, assembly and maintenance and reduces the failure rate.

[0068] This invention employs a unified electronic control system to support the coordinated motion of the planar moving platform 4 and the six-degree-of-freedom attitude adjustment mechanism 5, achieving efficient motion allocation and control strategies. The overall structure is compact and suitable for highly constrained environments, such as energy equipment manufacturing workshops. Furthermore, the vibration damping module 25 buffers vibrations during the transfer process, further protecting precision components and ensuring long-term reliable operation.

[0069] Application Example 1: This application example uses the docking and assembly of large rocket modules in the aerospace field as an example to explain in detail the complete motion process, functional division and branch coordination logic of this robot. The whole process is divided into two independent stages: the large-scale transfer stage and the precise attitude adjustment stage. The functions of the AGV planar mobile platform 4 and the six-degree-of-freedom attitude adjustment mechanism 5 are strictly decoupled. All mechanisms are marked with the corresponding patent numerical code, and the motion logic conforms to the branch coordination rules under the custom coordinate system.

[0070] I. Large-scale transfer stage: AGV planar mobile platform with 4 dedicated execution and a six-degree-of-freedom posture adjustment mechanism with 5 full-process locking at zero position.

[0071] This stage is completed independently by the planar moving platform 4AGV body. The first branch 9, the second branch 11, and the third branch 14 of the six-degree-of-freedom attitude adjustment mechanism 5 all remain in the initial zero position and have no driving action. The moving platform module 7 and the frame 6 remain relatively stationary.

[0072] Motion execution: The central processing unit 17 sends a transfer path command to the mobile platform control module 18. The servo motor driver 15 drives the first drive wheel group 8, the second drive wheel group 10, the third drive wheel group 12, and the fourth drive wheel group 13 at the bottom of the frame 6 to move synchronously. Each drive wheel group is powered by an independent wheel servo motor 23. After the torque is amplified by the planetary reducer 24, it drives the Mecanum wheel 27 to rotate through the transmission seat. Through the coordination of the speed and steering differential of the four Mecanum wheels 27, the omnidirectional movement of the vehicle body is realized, including forward and backward straight movement, left and right lateral movement, stationary rotation, and diagonal movement. This completes a large-scale transfer from the standby workstation to the target workstation for compartment assembly. During the transfer process, the shock absorption module 25 buffers the road vibration throughout the process to protect the precision components of the whole machine.

[0073] Position locking: When the AGV body reaches the preset target position, the wheel servo motor 23 of the 4 sets of drive wheels is locked, the Mecanum wheel 27 does not rotate, the frame 6 is absolutely fixed, the transfer stage ends, the six-degree-of-freedom attitude adjustment mechanism control module 16 is started, and the precise attitude adjustment stage begins.

[0074] II. Precise posture adjustment stage: The six-degree-of-freedom posture adjustment mechanism operates independently, and the AGV body is locked and fixed throughout the process.

[0075] In this stage, the frame 6 of the planar moving platform 4 is completely locked and has no displacement. The precise six-degree-of-freedom pose adjustment of the moving platform module 7 is completed only by the six-degree-of-freedom attitude adjustment mechanism 5 through the coordinated drive of the first branch 9, the second branch 11, and the third branch 14.

[0076] Custom reference coordinate system: The horizontal plane of the locked frame 6 is the XY reference plane, the forward direction of the vehicle body is the positive X-axis, the leftward direction of the vehicle body is the positive Y-axis, and the upward vertical direction is the positive Z-axis; the rotation around the X-axis is the roll degree of freedom, the rotation around the Y-axis is the pitch degree of freedom, and the rotation around the Z-axis is the yaw degree of freedom.

[0077] The six-degree-of-freedom (DOF) attitude adjustment mechanism 5 adopts a parallel control logic driven by three branches 6. The first branch 9 is welded to the front side of the frame 6, and the second branch 11 and the third branch 14 are symmetrically welded to the left and right sides of the frame 6, forming a tripod arrangement. Each branch includes two active degrees of freedom: a lateral sliding joint corresponding to the first lead screw 30 and a vertical sliding joint corresponding to the second lead screw 44. It also includes four passive degrees of freedom: one unidirectional rotation provided by the cross slider 32 and three rotations provided by the ball joint. Through the combination of active drive and passive compensation, six degrees of freedom motion is achieved without constraints. The chain coordination motion process for each degree of freedom is as follows: Z-axis vertical translation degree of freedom lifting and adjusting posture: The lateral moving joints of the first branch 9, the second branch 11, and the third branch 14 are locked in place throughout the entire movement, with only the vertical moving joints moving synchronously and in coordination. The second servo motors 37 of the first branch 9, the second branch 11, and the third branch 14 rotate synchronously and at the same speed. Through the second synchronous belt module 42, they drive the second lead screws 44 of the three branches to extend or retract in the same direction and with the same stroke. Through the second ball joint seat 41 on the second mounting plate 33 and the first ball joint seat 21 of the moving platform module 7, they synchronously drive the moving platform frame 20 to rise vertically upward or fall vertically along the Z-axis. The cross slider 32 and the inner ball 39 of the ball joint, the ball joint ball bearing 40, and the second ball joint seat 41 adaptively compensate for small angular deviations during the movement, completing the vertical lifting and lowering posture adjustment of the moving platform module 7.

[0078] X-axis translational degrees of freedom: The lateral moving joints of the second branch 11 and the third branch 14 on the left and right sides move synchronously and cooperatively, while the vertical moving joints are locked and stationary; the lateral moving joints of the first branch 9 on the front side are locked and stationary, while the vertical moving joints move in coordination.

[0079] Specifically, the first servo motors 34 of the second branch 11 and the third branch 14 rotate synchronously at the same speed, driving the first lead screws 30 of the two branches to extend forward or retract backward in the same direction and with the same stroke via the first synchronous belt module 35. Simultaneously, the second servo motor 37 of the first branch 9 drives the second lead screw 44 to perform an adaptive vertical extension or retraction. During the movement, the cross slider 32 of the first branch 9 provides one degree of freedom for passive unidirectional rotation, and the ball joint provides three degrees of freedom for passive rotation, ensuring that the entire motion chain is free from over-constraint, ultimately driving the moving platform module 7 to smoothly complete forward and backward translational adjustment along the X-axis.

[0080] Y-axis translational degrees of freedom: The lateral sliding joint of the first branch 9 on the front side moves, while the vertical sliding joint remains locked. The lateral sliding joints of the second branch 11 and the third branch 14 on the left and right sides remain locked, while the vertical sliding joints move in coordination. Specifically, the first servo motor 34 of the first branch 9 drives the first lead screw 30 to move laterally to the left or right; simultaneously, the second servo motors 37 of the second branch 11 and the third branch 14 synchronously drive the second lead screw 44 to perform adaptive vertical extension or retraction. During the movement, the cross sliders 32 of the second branch 11 and the third branch 14 provide one degree of freedom of passive unidirectional rotation, and the ball joint provides three degrees of freedom of passive rotation, eliminating motion constraints and ultimately driving the moving platform module 7 to smoothly complete left and right translation and posture adjustment along the Y-axis.

[0081] Taking the yaw degree of freedom about the Z-axis in a positive angle counterclockwise rotation as an example: The lateral sliding joints of the first branch 9, the second branch 11, and the third branch 14 all perform coordinated counterclockwise movements, while the vertical sliding joints of the three branches all perform small-amplitude upward movements to maintain the overall height of the moving platform module 7. Specifically, the first servo motors 34 of the first branch 9, the second branch 11, and the third branch 14 drive the first lead screw 30 to perform a counterclockwise lateral movement according to preset inverse kinematic parameters; simultaneously, the second servo motors 37 of the three branches synchronously drive the second lead screw 44 to perform a small upward movement. During the movement, the cross slider 32 of the three branches provides one degree of passive unidirectional rotation, and the ball joint provides three degrees of passive rotation, compensating for the positional deviation during the rotation process, ultimately driving the moving platform module 7 to complete a counterclockwise yaw attitude adjustment around the Z-axis at a set angle.

[0082] Taking the roll degree of freedom around the X-axis as an example, with positive angle rotation: The lateral and vertical sliding joints of the first branch 9 on the front side are locked and stationary; the lateral sliding joints of the second branch 11 and the third branch 14 on the left and right sides are locked and stationary, while the vertical sliding joints move in opposite directions in a coordinated manner.

[0083] Specifically, the second servo motor 37 of the second branch 11 on the left drives the second lead screw 44 to extend upward, while the second servo motor 37 of the third branch 14 on the right synchronously drives the second lead screw 44 to retract downward. The rotation speed and stroke of the two are precisely matched through kinematic calculations by the central processing unit 17. During the movement, the cross slider 32 of the second branch 11 and the third branch 14 provides one degree of passive unidirectional rotation, and the ball joint provides three degrees of passive rotation, ensuring no over-constraint. Ultimately, this drives the moving platform module 7 to complete a positive-direction roll adjustment around the X-axis at a set angle.

[0084] Taking the pitch degree of freedom around the Y-axis in positive angle rotation as an example: The lateral moving joint of the first branch 9 on the front side is locked and stationary, while the vertical moving joint moves downward; the lateral moving joints of the second branch 11 and the third branch 14 on the left and right sides move in coordination in the positive X-axis direction, while the vertical moving joints both move upward.

[0085] Specifically: the second servo motor 37 of the first branch 9 drives the second lead screw 44 to retract downwards; simultaneously, the first servo motors 34 of the second branch 11 and the third branch 14 synchronously drive the first lead screw 30 to move laterally in the positive X-axis direction, and the second servo motors 37 of the two branches synchronously drive the second lead screw 44 to extend upwards. During the movement, the cross slider 32 of the three branches provides one degree of passive unidirectional rotation, and the ball joint provides three degrees of passive rotation to compensate for the pose deviation, ultimately driving the moving platform module 7 to complete the positive pitch adjustment of the set angle around the Y-axis.

[0086] The aforementioned motion patterns are based on the currently set origin of the moving platform coordinate system. If the origin is adjusted, the specific motion parameters of the branches will change accordingly. However, the configuration of two active degrees of freedom and four passive degrees of freedom in a single branch can ensure the unconstrained realization of six degrees of freedom motion. In actual module docking and assembly, the central processing unit 17 can use inverse kinematics algorithm to synchronously drive the three branches to achieve composite cooperative motion of multiple degrees of freedom, completing the full-dimensional pose correction of the moving platform module 7 in one go.

[0087] The structural advantages of this invention make it particularly suitable for the high-load autonomous assembly needs in fields such as aerospace and large-scale machinery manufacturing, overcoming the limitations of existing technologies that make it difficult to balance load, stiffness, precision and scaling ratio.

Claims

1. A three-branch, six-DOF (degrees of freedom) parallel mobile composite robot, characterized in that: The vehicle body includes a carrier vehicle that moves with the planar moving platform (4), on which a six-degree-of-freedom attitude adjustment mechanism (5) and an electronic control module are installed. The top of the six-degree-of-freedom attitude adjustment mechanism (5) is provided with a moving platform module (7). The six-degree-of-freedom attitude adjustment mechanism (5) includes a first branch (9), a second branch (11) and a third branch (14). The first branch (9) is located on the front side of the frame (6), and the second branch (11) and the third branch (14) are located on the left and right sides of the frame (6) respectively. Each branch includes a lateral sliding joint and a vertical sliding joint connected by a cross slider (32). The lateral sliding joint is mounted on a first mounting plate (28) fixedly connected to the frame (6) and driven by a first lead screw (30). The vertical sliding joint is mounted on a second mounting plate (33) and driven by a second lead screw (44). The second mounting plate (33) is connected to the moving platform module (7) through a ball joint. The ball joint includes a second ball joint seat (41) disposed on the second mounting plate (33) and a first ball joint seat (21) disposed on the moving platform module (7). The second ball joint seat (41) is provided with a ball joint inner ball (39) and a ball joint ball bearing (40). The first ball joint seat (21) is connected to the second ball joint seat (41) by bolts and rotates in cooperation with the ball joint inner ball (39). The planar moving platform (4) has a locked state. When it is locked, the six-degree-of-freedom attitude adjustment mechanism (5) realizes the six-degree-of-freedom attitude adjustment of the moving platform module (7) through the coordinated movement of the horizontal and vertical moving joints of the three branches.

2. The three-branch, six-DOF (degrees of freedom) parallel mobile composite robot according to claim 1, characterized in that: The cross slider (32) includes a first cross shaft (47) and a second cross shaft (52). The end face of the first cross shaft (47) is provided with a first slider (48) connected to the groove of the first lead screw (30). The end face of the second cross shaft (52) is provided with a second slider (53) connected to the groove of the second lead screw (44). The first cross shaft (47) and the second cross shaft (52) are movably connected by a connecting shaft (51).

3. The three-branch, six-degree-of-freedom mobile parallel composite robot according to claim 2, characterized in that: The slots of the first slider (48) and the second slider (53) are perpendicular to each other in space.

4. The three-branch, six-degree-of-freedom mobile parallel composite robot according to claim 2, characterized in that: The connecting shaft (51) is mounted on bearings (50) at both ends. The bearings (50) are mounted on the first cross shaft (47), and bearing end caps (55) are mounted on both ends of the bearings (50). The bearing end caps (55) are fixed to the first cross shaft (47) by bolts.

5. A three-branch, six-degree-of-freedom mobile parallel composite robot according to claim 1, characterized in that: The lateral moving pair also includes a first guide rail seat (29), a second guide rail seat (36) and a first guide rail module (31) fixed to the first mounting plate (28) by bolts. The first guide rail seat (29) and the second guide rail seat (36) are fixed to the two ends of the first lead screw (30) respectively. The branch first servo motor (34) is fixed to the first mounting plate (28) by bolts, and the first lead screw (30) and the branch first servo motor (34) are connected by a first synchronous belt module (35).

6. A three-branch, six-degree-of-freedom mobile parallel composite robot according to claim 1, characterized in that: The vertical moving pair also includes a third guide rail seat (43), a fourth guide rail seat (46), and a second guide rail module (45) that are fixed to the second mounting plate (33) by bolts. The second lead screw (44) is fixed to the third guide rail seat (43) and the fourth guide rail seat (46) at both ends respectively. The branch second servo motor (37) is fixed to the second servo motor bracket (38) by bolts. The second servo motor bracket (38) is fixed to the second mounting plate (33) by bolts. The second lead screw (44) and the branch second servo motor (37) are connected through the second synchronous belt module (42).

7. A three-branch, six-DOF (degrees of freedom) parallel mobile composite robot according to claim 1, characterized in that: The planar moving platform (4) includes a first drive wheel set (8), a second drive wheel set (10), a third drive wheel set (12) and a fourth drive wheel set (13) bolted to the bottom of the frame (6). Each drive wheel set includes a Mecanum wheel (27) independently driven by a wheel set servo motor (23).

8. A three-branch, six-DOF (degrees of freedom) parallel mobile composite robot according to claim 7, characterized in that: The output end of the wheel servo motor (23) is connected to the planetary reducer (24), and the output end of the planetary reducer (24) drives the Mecanum wheel (27) through the transmission seat.

9. A three-branch, six-degree-of-freedom mobile parallel composite robot according to claim 8, characterized in that: The transmission seat is installed in the wheel set bracket (26), and a shock-absorbing module (25) for shock absorption is provided between the transmission seat and the wheel set bracket (26).

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