A rigid-flexible coupled collaborative aerospace blade grinding robot

Abstract

This invention relates to a rigid-flexible coupling collaborative aerospace blade grinding robot, comprising a frame, a lifting mechanism within the frame, and an auxiliary gripper, a conveyor belt, and a grinding mechanism at the bottom of the frame. The lifting mechanism includes a primary platform, a secondary platform, and a self-locking gripper arranged sequentially from top to bottom. The primary platform is connected to a first drum in the primary platform control mechanism via a first flexible cable, and the self-locking gripper is connected to a second drum in the gripper attitude control mechanism via a second flexible cable. As can be seen from the above technical solution, this invention features rigid-flexible coupling, high efficiency, modular reconfigurability, large workspace, stable grinding quality, and full-process automation. Furthermore, this robot can automatically complete clamping, omnidirectional grinding, and lifting tasks, and is adaptable to grinding aerospace blades of different sizes and structures.

Description

Technical Field

[0001] This invention relates to the field of collaborative robots, specifically to a rigid-flexible coupled collaborative aerospace blade grinding robot. Background Technology

[0002] Aero engines are crucial components of aircraft, and the surface quality of their blades directly impacts flight safety and stability, necessitating grinding to improve performance and extend service life. Traditional manual grinding heavily relies on worker skill levels and suffers from low production efficiency and inconsistent finish, failing to meet the high-quality, low-cost, and short-cycle requirements of today's aerospace manufacturing industry for complex curved surface parts. Similarly, existing multi-axis CNC grinding equipment features fixed processing methods, complex structures, and non-reconfigurable features, hindering mass production. Currently, with the continuous expansion of the aerospace market, the demand for aero blades is constantly increasing. Robotic grinding, as a more efficient mass production method, is widely used, but the efficiency of robotic arms remains limited, and manual loading and unloading of workpieces is still required throughout the process. These challenges mean that existing blade grinding methods and equipment cannot meet the needs of enterprises. For example, patent application number "CN202211611033.0" describes a grinding device and blade grinding method, which sets up the grinding components above the blade's work area, avoiding the need for a manual arm to hold the grinding components. However, the grinding process still requires manual intervention, and efficiency is not significantly improved. Another example is patent application number "CN202010635164.7," which describes a wind turbine blade grinding robot. Using multi-angle adjustment and telescopic mechanisms, it can perform fully automatic, stable, and efficient grinding of wind turbine blades, saving labor costs. However, it only has one robotic arm, and during the grinding process, the base needs to be constantly moved. Too many telescopic and adjustment structures also indirectly affect the grinding accuracy and increase the difficulty of control. Therefore, we need a fully automated, highly efficient, and collaborative aerospace blade grinding robot. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned drawbacks and provide a rigid-flexible coupled collaborative aerospace blade grinding robot. This robot features rigid-flexible coupling, high efficiency, modular reconfigurability, large workspace, stable grinding quality, and full-process automation. At the same time, the robot can automatically complete clamping and fixing, all-round grinding and hoisting tasks, and can be adapted to grinding aerospace blades of different sizes and structures.

[0004] To achieve the above object, the present invention adopts the following technical solutions: It includes a frame, within which a hoisting mechanism is provided. At the bottom of the frame, there are an auxiliary gripper, a conveyor belt, and a grinding mechanism. The hoisting mechanism includes a first-level platform, a second-level platform, and a self-locking gripper arranged successively from top to bottom. The first-level platform is connected to the top plate of the frame through a guiding rod, and a compression spring is sleeved on the guiding rod. The first-level platform and the second-level platform are connected by an electric telescopic rod in a variable stiffness mechanism. The second-level platform is fixed to the installation flat plate on the top of the self-locking gripper. The first-level platform is connected to the first reel in the first-level platform control mechanism through a first flexible cable. The self-locking gripper is connected to the second reel in the gripper attitude control mechanism through a second flexible cable. The rubber jaws in the self-locking gripper are used to grip the root end of the blade to be polished, and the pneumatic jaws in the auxiliary gripper are used to grip the blade end of the blade to be polished.

[0005] The self-locking gripper includes an installation flat plate fixed to the second-level platform. On the lower surface of the installation flat plate, four groups of flexible clamping modules with the same structure and distributed in a "field" shape are fixed, and the four groups of flexible clamping modules are successively rotated 90°.

[0006] The flexible clamping module includes a housing and two groups of self-locking cylinders arranged side by side within the housing. The self-locking cylinder is a hollow columnar body with one end closed and one end open. Along the circumferential direction of the outer wall of the self-locking cylinder, three groups of straight-strip first stopping grooves are provided, and the setting direction of the first stopping grooves coincides with the axial direction of the self-locking cylinder. Between adjacent two groups of first stopping grooves, two groups of inclined teeth arranged continuously are provided, and a second stopping groove is formed between the two groups of inclined teeth. The inclined teeth are composed of a vertical surface and an inclined sliding surface. In the initial state, the self-locking rod arranged inside the housing is engaged with any one of the three groups of first stopping grooves or the three groups of second stopping grooves.

[0007] The flexible clamping module further includes a flexible cable guiding block, a fixed pulley, a pushing pulley, and a flexible cable fixing block located on the upper surface of the housing and cooperating with the second flexible cable. The second flexible cable passes through the guiding hole in the flexible cable guiding block and then successively winds around the fixed pulley, the pushing pulley, and is fixed to the flexible cable fixing block.

[0008] The flexible clamping module further includes a gripper assembly, which includes a first cylindrical rod vertically penetrating the housing. The orientation of the first cylindrical rod coincides with the axial direction of the self-locking cylinder. Two sets of the first cylindrical rods are arranged side by side. The end of the first cylindrical rod outside the housing is fixed to the upright plate, and the end of the first cylindrical rod inside the housing is fixed to the first circular connecting plate. The first circular connecting plate is connected to the closed end of the self-locking cylinder through a one-way thrust ball bearing. A first rebound spring is sleeved on the first cylindrical rod inside the housing. The two ends of the first rebound spring are respectively fixed to the first circular connecting plate and the inner wall of the housing. A rubber gripper is connected to the bottom of the upright plate. The rubber gripper is located below the housing, and the rubber grippers in the four sets of flexible clamping modules together form a clamping part.

[0009] The flexible clamping module further includes a pushing component, which includes an I-shaped slider that engages with a groove inside the housing. The upper surface of the slider is fixed to the axle of the pushing pulley. Pushing members are provided on the left and right sides of the slider. Each pushing member includes an arc-shaped connecting rod fixed to the slider and a strip-shaped push rod fixed to the arc-shaped connecting rod. The sliding direction of the slider and the setting direction of the strip-shaped push rod are both aligned with the axial direction of the self-locking cylinder. The end of the strip-shaped push rod is inclined. The strip-shaped push rod is parallel to and tangent to the self-locking rod. The release and retraction of the second flexible cable causes the slider to slide along the direction defined by the groove. During the sliding of the slider, the strip-shaped push rod abuts against or separates from the inclined sliding surface on the self-locking cylinder. The pushing component also includes a second cylindrical rod and a second return spring. One end of the second cylindrical rod is vertically connected to the axle of the pushing pulley, and the other end of the second cylindrical rod is provided with a second circular connecting plate. The two ends of the second return spring are fixed to the second circular connecting plate and a baffle provided on the housing, respectively.

[0010] The overall shape of the housing is square, and it is formed by the combination of a first housing and a second housing arranged in the vertical direction; the flexible cable guide block is located at one corner of the upper surface of the first housing, and the other three corners of the upper surface of the first housing are respectively provided with columns that are bolted to the mounting plate. The flexible cable guide blocks in the four sets of flexible clamping modules are respectively located at the four corners of the mounting plate.

[0011] The first housing is provided with a first groove that cooperates with the shaft of the push pulley and a second groove that cooperates with the second rebound spring. The first groove and the second groove are connected. The baffle is fixed to the end of the second groove away from the first groove.

[0012] The first housing and the second housing have semi-circular grooves on their mating end faces to accommodate self-locking cylinders. The sliding groove is provided on the second housing and is located in the middle of the two sets of semi-circular grooves on the second housing. A self-locking rod is provided at the bottom of the semi-circular groove in the second housing. The arc-shaped connecting rod is fitted to the semi-circular groove of the second housing.

[0013] The primary platform control mechanism includes a first drum, a first motor that drives the first drum to rotate, and a first guide pulley assembly that cooperates with a first flexible cable. The first guide pulley assembly includes a first guide pulley fixed to the upper surface of the frame top plate and a second guide pulley fixed to the lower surface of the frame top plate. The first drum and the first motor are both fixed to the upper surface of the frame top plate through a first drum bracket. One end of the first flexible cable is fixed to the first drum, and the other end of the first flexible cable passes through the first guide pulley and the second guide pulley in sequence before being fixed to the primary platform.

[0014] The primary platform is a triangular platform. The first flexible cable and the primary platform control mechanism are each provided in three sets. The three sets of first flexible cables are fixed to the three sides of the primary platform. The three sets of primary platform control mechanisms are arranged in an equilateral triangle shape at the center of the frame top plate. The three sets of first flexible cables are all double cable structures arranged in parallel.

[0015] One end of the guide rod is connected to the center of the frame top plate through a rubber sleeve, and the other end of the guide rod is connected to the center of the first-level platform through a ball joint. The two ends of the compression spring are fixed to the lower surface of the frame top plate and the upper surface of the first-level platform, respectively. When the first drum drives the first flexible cable to retract and extend, the guide rod moves up and down inside the rubber sleeve, and the compression spring is always in a compressed state.

[0016] The variable stiffness mechanism includes an electric telescopic rod connecting the primary platform and the secondary platform. The seat end of the electric telescopic rod is connected to the center of the primary platform via a first ball joint, and the rod end of the electric telescopic rod is connected to the center of the secondary platform via a second ball joint. The variable stiffness mechanism also includes a square bushing and a spring assembly connecting the square bushing and the secondary platform. The square bushing is sleeved on the seat of the electric telescopic rod and fixedly connected to the seat. The spring assembly includes four sets of springs. One end of each set of springs is connected to one of the four sides of the square bushing, and the other end of each set of springs is connected to the secondary platform.

[0017] The square bushing has a semi-circular buckle at the center of each of its four sides, which cooperates with the spring. The secondary platform has four sets of lifting rings that cooperate with the spring. The positions of the lifting rings correspond to the positions of the semi-circular buckles, and the center points of the four sets of semi-circular buckles are collinear with the center points of the four sets of lifting rings.

[0018] The auxiliary clamp includes a base and a rotating seat rotatably connected above the base. The base is equipped with a third motor that drives the rotating seat to rotate. The upper surface of the rotating seat has a mounting groove along its radial direction. Pneumatic grippers are symmetrically arranged on the two side walls of the mounting groove.

[0019] The gripper attitude control mechanism includes a second drum, a second motor that drives the second drum to rotate via a synchronous belt pulley mechanism, a reversing pulley group and a second guide pulley group that cooperate with the second flexible cable, and a variable stiffness pulley mechanism for adjusting the stiffness of the second flexible cable. The second drum is fixed to the upper surface of the frame top plate by a mounting plate. The second drum is a non-uniform diameter drum, including a large-diameter drum section and a small-diameter drum section arranged coaxially. The large-diameter drum section is fixed to the second flexible cable, and the small-diameter drum section is fixed to the variable stiffness flexible cable in the variable stiffness pulley mechanism. The winding directions of the second flexible cable and the variable stiffness flexible cable are opposite, and the diameter of the second flexible cable is larger than the diameter of the variable stiffness flexible cable.

[0020] The reversing pulley assembly includes a first reversing pulley, a second reversing pulley, and a third reversing pulley fixed to the upper surface of the mounting plate. The second guide pulley assembly includes a third guide pulley fixed to the upper surface of the mounting plate and a fourth guide pulley fixed to the lower surface of the frame top plate. The variable stiffness pulley mechanism is disposed between the first reversing pulley and the second reversing pulley.

[0021] The variable stiffness pulley mechanism includes a variable stiffness flexible cable, a variable stiffness sliding pulley, a return spring, a first spring fixing seat and a second spring fixing seat fixed to both ends of the return spring. One end of the variable stiffness flexible cable is fixed to the small-diameter section of the second drum, and the other end of the variable stiffness flexible cable is fixed to the axle of the variable stiffness sliding pulley. One end of the second flexible cable is fixed to the large-diameter section of the second drum. The other end of the second flexible cable passes sequentially through the first reversing pulley, the variable stiffness sliding pulley, the second reversing pulley, the third reversing pulley, the third guide pulley, and the fourth guide pulley before connecting to the self-locking clamp.

[0022] The mounting plate has a groove for accommodating a variable stiffness sliding pulley. The width of the groove matches the diameter of the variable stiffness sliding pulley. A through slot is formed along the length of the groove bottom. The axle of the variable stiffness sliding pulley passes through this through slot and is fixedly connected to the second spring fixing seat. The first spring fixing seat is on the lower surface of the mounting plate. The winding and unwinding of the variable stiffness flexible cable causes the variable stiffness sliding pulley to slide in the groove to ensure the stiffness of the second flexible cable. A protective cover is provided above the mounting plate. The top plate of the frame has notches for avoiding the rebound spring, the first spring fixing seat, and the second spring fixing seat.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. The hoisting mechanism of the present invention uses a flexible cable parallel connection to drive the end self-locking gripper. Compared with traditional rigid robots, the flexible cable parallel robot has the advantages of large working space and low inertia when facing the hoisting work of aircraft blades. It also has high flexibility when combined with the grinding mechanism.

[0025] 2. This invention adopts a two-stage structure. The first-stage platform control mechanism controls the rapid translation of the self-locking gripper, which improves the efficiency of the hoisting process where the precision requirements are not high. Compared with the single-stage structure, it increases the working space while improving the motion stability and precision of the end self-locking gripper.

[0026] 3. The self-locking clamp of the present invention is driven by a second flexible cable, which turns the defect of the flexible cable being only under tension and not under pressure into an advantage. The opening and closing of the end self-locking clamp is realized by pulling the second flexible cable, which improves the self-locking stability and control difficulty of the blade clamping process and reduces the weight and energy consumption of the driving components.

[0027] 4. The secondary platform of this invention is a variable stiffness platform. Traditional flexible cable parallel mechanisms cannot maintain stability when facing external impacts. The electric telescopic rod inside the variable stiffness secondary platform and the entire variable stiffness mechanism improve the structural stiffness during the hoisting and grinding of aero-blades, and improve the grinding stability.

[0028] 5. The second drum of the present invention is a non-uniform diameter variable stiffness drum, which uses a single motor and a single drum to control the opposite movement of two flexible cables of different thicknesses. When the second flexible cable is extended, the stiffness of the flexible cable is increased, and when the second flexible cable is tightened, the stability is improved.

[0029] 6. The hoisting platform and self-locking gripper of the present invention have the advantages of modularity and reconfigurability, and can be robotically reconfigured to meet the grinding requirements of different working conditions and blades of different sizes and structures. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention;

[0031] Figure 2 This is a structural schematic diagram of the primary platform, secondary platform, and variable stiffness mechanism of the present invention;

[0032] Figure 3 This is a schematic diagram of the primary platform control mechanism and the connection structure between the primary platform and the frame top plate of the present invention;

[0033] Figure 4 This is a schematic diagram of the structure of the auxiliary clamp of the present invention;

[0034] Figure 5 This is a schematic diagram of the gripper attitude control mechanism of the present invention;

[0035] Figure 6This is a schematic diagram of the connection structure between the variable stiffness sliding pulley and the second spring fixing seat of the present invention;

[0036] Figure 7 This is a schematic diagram of the internal structure of the gripper attitude control mechanism of the present invention after the protective cover has been removed. Figure 1 ;

[0037] Figure 8 This is a schematic diagram of the internal structure of the gripper attitude control mechanism of the present invention after the protective cover has been removed. Figure 2 ;

[0038] Figure 9 This is a schematic diagram of the structure of the self-locking clamp of the present invention;

[0039] Figure 10 This is an exploded structural diagram of the self-locking gripper of the present invention;

[0040] Figure 11 This is a bottom view of the four sets of flexible clamping modules of the present invention;

[0041] Figure 12 This is a schematic diagram of the structure of the single flexible clamping module of the present invention. Figure 1 ;

[0042] Figure 13 This is a schematic diagram of the structure of the single flexible clamping module of the present invention. Figure 2 ;

[0043] Figure 14 This is a schematic diagram of the internal structure of the single flexible clamping module of the present invention after the first shell is removed;

[0044] Figure 15 This is a schematic diagram of the structure of the first housing of the present invention. Figure 1 ;

[0045] Figure 16 This is a schematic diagram of the structure of the first housing of the present invention. Figure 2 ;

[0046] Figure 17 This is a schematic diagram of the structure of the second housing of the present invention. Figure 1 ;

[0047] Figure 18 This is a schematic diagram of the connection structure between the push pulley and the push assembly of the present invention;

[0048] Figure 19 This is a schematic diagram of the connection structure between the gripper assembly and the one-way thrust ball bearing of the present invention;

[0049] Figure 20 This is a schematic diagram of the gripper assembly of the present invention;

[0050] Figure 21 This is a schematic diagram of the structure of the self-locking cylinder of the present invention;

[0051] Figure 22 This is a schematic diagram of the rotation of the self-locking cylinder during the process of the rubber gripper of the present invention from clamping to opening.

[0052] The labels in the above figures are as follows: Frame 1, Frame top plate 11, Auxiliary clamp 12, Base 121, Rotary base 122, Third motor 123, Mounting slot 124, Pneumatic gripper 125, Conveyor belt 13, Grinding mechanism 14, Primary platform 2, Guide rod 21, Rubber sleeve 211, Compression spring 22, Secondary platform 3, Lifting ring 31, Self-locking clamp 4, Mounting plate 41, Housing 42, First housing 421, First groove 4211, Second groove 4212, Baffle 4213, Second housing 4 22. Slide groove 4221, self-locking rod 4222, column 423, self-locking cylinder 43, first stop groove 431, second stop groove 432, helical tooth 433, vertical surface 4331, inclined sliding surface 4332, flexible cable guide block 44, fixed pulley 45, push pulley 46, flexible cable fixing block 47, gripper assembly 48, first cylindrical rod 481, upright plate 482, first circular connecting plate 483, one-way thrust ball bearing 484, first rebound spring 485, rubber gripper 486, push assembly 49, slider 4 91. Arc-shaped connecting rod; 492. Strip-shaped push rod; 493. Second cylindrical rod; 494. Second rebound spring; 495. Second circular connecting plate; 496. First flexible cable; 5. Second flexible cable; 6. First-level platform control mechanism; 7. First drum; 71. First motor; 72. First guide pulley; 73. Second guide pulley; 74. First drum support; 75. Clamping device posture control mechanism; 8. Second drum; 81. Large-diameter drum section; 811. Small-diameter drum section; 812. Second motor; 82. Mounting plate; 83. Groove; 831. Through slot; 8 32. Protective cover 833. Variable stiffness pulley mechanism 84. Variable stiffness flexible cable 841. Variable stiffness sliding pulley 842. Rebound spring 843. First spring fixing seat 844. Second spring fixing seat 845. First reversing pulley 85. Second reversing pulley 86. Third reversing pulley 87. Third guide pulley 88. Fourth guide pulley 89. Variable stiffness mechanism 9. Electric telescopic rod 91. First ball joint 92. Second ball joint 93. Square bushing 94. Semi-circular ring buckle 941. Spring 95. Blade to be ground 10. Detailed Implementation

[0053] The present invention will be further described below with reference to the accompanying drawings:

[0054] like Figure 1The illustrated rigid-flexible coupling collaborative aerospace blade grinding robot includes a frame 1, within which a hoisting mechanism is installed. At the bottom of the frame 1 are an auxiliary gripper 12, a conveyor belt 13, and a grinding mechanism 14. In this embodiment, the auxiliary gripper 12, conveyor belt 13, and grinding mechanism 14 are placed on the ground at the bottom of the frame 1. The hoisting mechanism includes a primary platform 2, a secondary platform 3, and a self-locking gripper 4 arranged sequentially from top to bottom. The primary platform 2 is connected to the first reel 71 in the primary platform control mechanism 7 via a first flexible cable 5. The self-locking gripper 4 is connected to the second reel 81 in the gripper attitude control mechanism 8 via a second flexible cable 6. The rubber gripper 486 in the self-locking gripper 4 is used to grip the root end of the blade 10 to be ground, and the pneumatic gripper 125 in the auxiliary gripper 12 is used to grip the blade tip of the blade 10 to be ground.

[0055] Furthermore, such as Figure 3 As shown, the primary platform 2 is connected to the top plate 11 of the frame via a guide rod 21, and a compression spring 22 is fitted onto the guide rod 21. Specifically, one end of the guide rod 21 is connected to the center of the top plate 11 of the frame via a deformable rubber sleeve 211, and this end extends out of the top plate 11, providing rigid support for the primary platform 2; the other end of the guide rod 21 is connected to the center of the primary platform 2 via a ball joint, providing stability for the movement of the primary platform 2. The two ends of the compression spring 22 are fixed to the lower surface of the top plate 11 of the frame and the upper surface of the primary platform 2, respectively. When the first drum 71 drives the first flexible cable 5 to retract, the guide rod 21 moves up and down within the rubber sleeve 211, and the compression spring 22 is always in a compressed state. That is, when the first flexible cable 5 controls the movement of the primary platform 2, the compression spring 22 is always under pressure, providing tension to the first flexible cable 5 and ensuring the stiffness of the first flexible cable 5.

[0056] Furthermore, such as Figure 3 As shown, the primary platform control mechanism 7 includes a first drum 71, a first motor 72 that drives the first drum 71 to rotate, and a first guide pulley group that cooperates with the first flexible cable 5. The first guide pulley group includes a first guide pulley 73 fixed to the upper surface of the frame top plate 11 and a second guide pulley 74 fixed to the lower surface of the frame top plate 11. The first drum 71 and the first motor 72 are both fixed to the upper surface of the frame top plate 11 through the first drum bracket 75. One end of the first flexible cable 5 is fixed to the first drum 71, and the other end of the first flexible cable 5 is fixed to the primary platform 2 after passing through the first guide pulley 73 and the second guide pulley 74 in sequence.

[0057] In this embodiment, the primary platform 2 is a triangular platform. Three sets of the first flexible cables 5 and the primary platform control mechanisms 7 are respectively provided. The three sets of the first flexible cables 5 are respectively fixed to the three sides of the primary platform 2. Preferably, the three sets of the first flexible cables 5 are double-cable structures arranged side by side, that is, a total of six first flexible cables 5 are provided. The three sets of primary platform control mechanisms 7 are arranged in an equilateral triangle shape at the center of the frame top plate 11. Correspondingly, three sets of the first guiding pulley groups are also provided. The planar movement of the primary platform 2 within the XOY plane is restricted within the triangular area formed by the three sets of the first guiding pulley groups.

[0058] Further, as Figure 2 shown, the primary platform 2 and the secondary platform 3 are connected by the electric telescopic rod 91 in the variable stiffness mechanism 9. The secondary platform 3 and the mounting plate 41 at the top of the self-locking gripper 4 are fixed by bolts. Specifically, the variable stiffness mechanism 9 includes the electric telescopic rod �1 connecting the primary platform 2 and the secondary platform 3. The seat end of the electric telescopic rod 91 is connected to the center of the primary platform 2 through the first ball joint 92, and the rod end of the electric telescopic rod 91 is connected to the center of the secondary platform 3 through the second ball joint 93. The electric telescopic rod 91 is used to control the vertical distance between the primary platform 2 and the secondary platform 3. The variable stiffness mechanism 9 further includes a square bushing 94 and a spring group connecting the square bushing 94 and the secondary platform 3. The square bushing 94 is sleeved on the seat body of the electric telescopic rod 91 and fixedly connected to the seat body. The spring group includes a total of four springs 95. One ends of the four springs 95 are respectively connected to the four sides of the square bushing 94, and the other ends of the four springs 95 are respectively connected to the secondary platform 3. The spring group in the variable stiffness mechanism 9 can improve the compliance during the extension of the electric telescopic rod 91 and can also improve the overall stiffness of the secondary platform 3. Specifically, semi-circular snap rings 941 cooperating with the springs 95 are respectively provided at the centers of the four sides of the square bushing 94. Four suspension rings 31 cooperating with the springs 95 are provided on the secondary platform 3. The positions of the suspension rings 31 correspond to the positions of the semi-circular snap rings 941, and the centers of the four semi-circular snap rings 941 and the centers of the four suspension rings 31 are collinear.

[0059] Further, as Figure 9 、 Figure 10 、 Figure 11 shown, the self-locking gripper 4 includes a mounting plate 41 fixed to the secondary platform 3. Four flexible clamping modules with the same structure and arranged in a "field" shape are fixed to the lower surface of the mounting plate 41. The four flexible clamping modules are sequentially rotated 90°. The planar movement of the secondary platform 3 can drive the planar movement of the self-locking gripper

[0060] Even further, as Figure 12 、 Figure 13 、 Figure 14As shown, the flexible clamping module includes a housing 42 and two sets of self-locking cylinders 43 arranged side-by-side within the housing 42. Figure 21 As shown, the self-locking cylinder 43 is a hollow columnar body with one end closed and the other end open. The outer wall of the self-locking cylinder 43 is provided with three sets of straight first stop grooves 431 along the circumference. The setting direction of the first stop grooves 431 coincides with the axial direction of the self-locking cylinder 43. Two sets of helical teeth 433 are arranged continuously between two adjacent sets of first stop grooves 431. A second stop groove 432 is formed between the two sets of helical teeth 433. The helical teeth 433 are composed of a vertical surface 4331 and a helical sliding surface 4332. In the initial state, the self-locking rod 4222 set inside the housing 42 engages with any one of the three sets of first stop grooves 431 or the three sets of second stop grooves 432.

[0061] Furthermore, the flexible clamping module also includes a flexible cable guide block 44, a fixed pulley 45, a push pulley 46, and a flexible cable fixing block 47 located on the upper surface of the housing 42 and cooperating with the second flexible cable 6. After the second flexible cable 6 passes through the guide hole in the flexible cable guide block 44, it passes around the fixed pulley 45 and the push pulley 46 in sequence and is fixed to the flexible cable fixing block 47.

[0062] Furthermore, such as Figure 19 , Figure 20 As shown, the flexible clamping module also includes a gripper assembly 48. The gripper assembly 48 includes a first cylindrical rod 481 that is vertically inserted through the housing 42. The direction of the first cylindrical rod 481 is consistent with the axial direction of the self-locking cylinder 43. Two sets of the first cylindrical rod 481 are arranged side by side. One end of the first cylindrical rod 481 outside the housing 42 is fixed to the upright plate 482, and the other end of the first cylindrical rod 481 inside the housing 42 is fixed to the first circular connecting plate 483. The first circular connecting plate 483 is connected to the closed end of the self-locking cylinder 43 through a one-way thrust ball bearing 484. A first rebound spring 485 is sleeved on the first cylindrical rod 481 inside the housing 42. The two ends of the first rebound spring 485 are respectively fixed to the first circular connecting plate 483 and the inner wall of the housing 42. A rubber gripper 486 is connected to the bottom of the upright plate 482. The rubber gripper 486 is located below the housing 42, and the rubber grippers 486 in the four sets of flexible clamping modules together form a clamping part.

[0063] Furthermore, such as Figure 18As shown, the flexible clamping module also includes a pushing component 49, which includes an I-shaped slider 491. The slider 491 cooperates with a groove 4221 in the housing 42, and the upper surface of the slider 491 is fixed to the axle of the pushing pulley 46. Pushing members are provided on the left and right sides of the slider 491, and the pushing members include an arc-shaped connecting rod 492 fixed to the slider 491 and a strip-shaped push rod 493 fixed to the arc-shaped connecting rod 492. The sliding direction of the slider 491 and the setting direction of the strip-shaped push rod 493 are both consistent with the axial direction of the self-locking cylinder 43. The end of the strip-shaped push rod 493 is a bevel. The strip-shaped push rod 493 and the self-locking rod 4221 are connected. The 22 phases are arranged in parallel and tangential positions. The extension and retraction of the second flexible cable 6 causes the slider 491 to slide along the direction defined by the slide groove 4221. During the sliding of the slider 491, the strip-shaped push rod 493 abuts against or separates from the inclined sliding surface 4332 on the self-locking cylinder 43. The pushing assembly 49 also includes a second cylindrical rod 494 and a second rebound spring 495. One end of the second cylindrical rod 494 is vertically connected to the axle of the pushing pulley 46, and the other end of the second cylindrical rod 494 is provided with a second circular connecting plate 496. The two ends of the second rebound spring 495 are respectively fixed to the second circular connecting plate 496 and the baffle 4213 provided on the housing 42. Under the condition of no external force, the second rebound spring 495 can ensure that the pushing component is in the initial position.

[0064] Furthermore, such as Figure 10 As shown, the housing 42 is generally square and is formed by the combination of a first housing 421 and a second housing 422 arranged in the vertical direction; the flexible cable guide block 44 is located at one corner of the upper surface of the first housing 421, and the other three corners of the upper surface of the first housing 421 are respectively provided with columns 423 bolted to the mounting plate 41, and the flexible cable guide blocks 44 in the four sets of flexible clamping modules are respectively located at the four corners of the mounting plate 41.

[0065] Furthermore, such as Figure 15 , Figure 16 , Figure 17 As shown, the first housing 421 is provided with a first groove 4211 that cooperates with the axle of the push pulley 46 and a second groove 4212 that cooperates with the second return spring 495. The first groove 4211 and the second groove 4212 are connected. The baffle 4213 is fixed to the end of the second groove 4212 away from the first groove 4211. The mating end faces of the first housing 421 and the second housing 422 are respectively provided with semi-circular grooves for accommodating the self-locking cylinder 43. The sliding groove 4221 is provided on the second housing 422, and the sliding groove 4221 is located in the middle of the two sets of semi-circular grooves of the second housing 422. The bottom of the semi-circular groove in the second housing 422 is provided with a self-locking rod 4222. The arc-shaped connecting rod 492 is provided in the semi-circular groove of the second housing 422.

[0066] During operation, when the second flexible cable 6 is stressed, pushing the pulley 46 to drive the pushing assembly 49 to overcome the elastic force of the second return spring 495 and move within the slide groove 4221, the strip-shaped push rod 493 in the pushing member 424 will push the self-locking cylinder 43 and the one-way thrust ball bearing 484 to overcome the elastic force of the first return spring 485, thereby pushing the rubber gripper 486 to extend and clamp the blade 10 to be ground. During the pushing process, due to the structure of the inclined sliding surface 4332 and the stop groove on the outer surface of the self-locking cylinder 43, and the close contact between the self-locking cylinder 43 and the one-way thrust ball bearing 484, the self-locking cylinder 43 will rotate during the movement. Thus, with each push of the pushing member, the first... The first stop groove 431 and the second stop groove 432 will alternately engage with the self-locking rod 4222 protruding inside the second housing 422. When the self-locking rod 4222 engages with the second stop groove 432, the rubber gripper 486 will retract a certain distance, thereby releasing the blade 10 to be polished. When the self-locking rod 4222 engages with the first stop groove 431, the rubber gripper 486 will extend and self-lock because the self-locking cylinder 43 cannot rotate, tightly clamping the blade 10 to be polished until the second flexible cable 6 is pulled and the push assembly 49 is released. This ensures that the self-locking clamp 4 can clamp, self-lock and release the blade 10 to be polished by only utilizing the characteristic that the second flexible cable 6 can only provide tension.

[0067] Furthermore, such as Figure 4 As shown, the auxiliary clamp 12 includes a base 121 and a rotating seat 122 rotatably connected above the base 121. The base 121 houses a third motor 123 that drives the rotating seat 122 to rotate. The upper surface of the rotating seat 122 has a radially formed mounting groove 124, and pneumatic grippers 125 are symmetrically arranged on both sides of the mounting groove 124. The third motor 123 controls the rotation of the rotating seat 122 and the pneumatic grippers 125 around the Z-axis, facilitating the gripper 125 to hold the blade end of the blade 10 to be ground. Simultaneously, the rotation of the blade 10 to be ground within a certain angle around the Z-axis can be adjusted during grinding.

[0068] Furthermore, such as Figure 5 , Figure 6 , Figure 7 , Figure 8As shown, the gripper attitude control mechanism 8 includes a second drum 81, a second motor 82 that drives the second drum 81 to rotate via a synchronous belt pulley mechanism, a reversing pulley group and a second guide pulley group that cooperate with the second flexible cable 6, and a variable stiffness pulley mechanism 84 that adjusts the stiffness of the second flexible cable 6. The second drum 81 is fixed to the upper surface of the frame top plate 11 by a mounting plate 83. The second drum 81 is a non-uniform diameter drum, including a large-diameter drum section 811 and a small-diameter drum section 812 arranged coaxially. The large-diameter drum section 811 is fixed to the second flexible cable 6, and the small-diameter drum section 812 is fixed to the variable stiffness flexible cable 841 in the variable stiffness pulley mechanism 84. The winding directions of the second flexible cable 6 and the variable stiffness flexible cable 841 are opposite, and the diameter of the second flexible cable 6 is larger than the diameter of the variable stiffness flexible cable 841. In this embodiment, four sets of gripper attitude control mechanisms 8 are provided, and the four sets of gripper attitude control mechanisms 8 are located at the four corners of the frame top plate 11.

[0069] Furthermore, the reversing pulley assembly includes a first reversing pulley 85, a second reversing pulley 86, and a third reversing pulley 87 fixed on the upper surface of the mounting plate 83. The second guide pulley assembly includes a third guide pulley 88 fixed on the upper surface of the mounting plate 83 and a fourth guide pulley 89 fixed on the lower surface of the frame top plate 11. The variable stiffness pulley mechanism 84 is disposed between the first reversing pulley 85 and the second reversing pulley 86. Specifically, the variable stiffness pulley mechanism 84 includes a variable stiffness flexible cable 841, a variable stiffness sliding pulley 842, a rebound spring 843, a first spring fixing seat 844 and a second spring fixing seat 845 fixed to both ends of the rebound spring 843. One end of the variable stiffness flexible cable 841 is fixed to the small diameter drum section 812 of the second drum 81, and the other end of the variable stiffness flexible cable 841 is fixed to the wheel axle of the variable stiffness sliding pulley 842. One end of the second flexible cable 6 is fixed to the large diameter drum section 811 of the second drum 81, and the other end of the second flexible cable 6 passes sequentially through the first reversing pulley 85, the variable stiffness sliding pulley 842, the second reversing pulley 86, the third reversing pulley 87, the third guide pulley 88, and the fourth guide pulley 89 before being connected to the self-locking clamp 4.

[0070] The fact that the second flexible cable 6 and the variable stiffness flexible cable 841 are wound in opposite directions ensures that when the second drum 81 rotates to lengthen the second flexible cable 6, the variable stiffness flexible cable 841 contracts, causing the variable stiffness sliding pulley 842 to move towards the second drum 81 against the tension of the return spring 843. This counteracts the elastic change of the second flexible cable 6 during its elongation, ensuring the stiffness of the second flexible cable 6. When the second drum 81 rotates to tighten the second flexible cable 6, the tension of the second flexible cable 6 is buffered by the thrust of the return spring 843 through the variable stiffness sliding pulley 842, further ensuring the stability and stiffness of the second flexible cable 6.

[0071] Furthermore, the mounting plate 83 has a groove 831 for accommodating the variable stiffness sliding pulley 842. The width of the groove 831 matches the diameter of the variable stiffness sliding pulley 842. A through groove 832 is formed at the bottom of the groove 831 along its length. The axle of the variable stiffness sliding pulley 842 passes through this through groove 832 and is fixedly connected to the second spring fixing seat 845. The first spring fixing seat 844 is on the lower surface of the mounting plate 83. The winding and unwinding of the variable stiffness flexible cable 841 causes the variable stiffness sliding pulley 842 to slide in the groove 831 to ensure the stiffness of the second flexible cable 6. A protective cover 833 is provided above the mounting plate 83. The top plate 11 of the frame is provided with notches for the avoidance rebound spring 843, the first spring fixing seat 844, and the second spring fixing seat 845.

[0072] The grinding mechanism 14 of the present invention includes a multi-jointed robotic arm and a grinding head connected to the end joint, the specific structure of which refers to the prior art. At the same time, in order to facilitate the self-locking gripper 4 to pick up and put down the blade 10 to be ground on the conveyor belt 13, a frame can be set on the conveyor belt 13 so that the blade 10 to be ground is placed with the root end facing upward.

[0073] The invention also includes a control system, which comprises a main industrial computer with a communication interface, a main controller with a communication module, a human-machine interface, and a feedback module. The human-machine interface is connected to the main industrial computer, which is communicatively connected to the main controller. The input terminals of various motor drivers are connected to the main controller via a CNC bus. The feedback module includes a laser rangefinder, a wire displacement sensor, an angular velocity sensor, a grating displacement sensor, and a vision sensor. The data output terminals of these sensors are connected to the feedback input terminals of the main controller. In this embodiment, two laser rangefinders are provided, both mounted on the frame 11; seven wire displacement sensors are provided, respectively mounted on the primary platform control mechanism 7 and the gripper attitude control mechanism 8; two angular velocity sensors are provided, one mounted on the secondary platform 3 and the other mounted on the rotating seat 122 of the auxiliary gripper 12; one grating displacement sensor is provided, mounted on the electric telescopic rod 91; and one vision sensor is provided, mounted on the side of the frame 11 near the grinding mechanism 14.

[0074] The working principle and process of this invention are as follows:

[0075] 1. In this invention, the first flexible cable is routed as follows: one end of the first flexible cable is fixedly connected to the first drum, and the other end of the first flexible cable passes through the first guide pulley and the second guide pulley in sequence before being fixed to the first-level platform.

[0076] 2. In this invention, the second flexible cable is routed as follows: one end of the second flexible cable is fixedly connected to the large-diameter section of the second drum, and the other end of the second flexible cable passes sequentially around the first directional pulley, the variable stiffness sliding pulley, the second directional pulley, the third directional pulley, the third guide pulley, and the fourth guide pulley before passing through the flexible cable guide block on the self-locking clamp. After passing through the flexible cable guide block, the second flexible cable passes sequentially around the fixed pulley and the push pulley before being fixed to the flexible cable fixing block.

[0077] 3. The operating principle of the primary and secondary platforms is as follows: When the self-locking gripper needs to move a large distance, the main controller drives the first motor to operate, the first drum rotates, and the six first flexible cables are wound and released in coordination. At the same time, the four second flexible cables are wound and released synchronously to cooperate with the first flexible cables, thereby achieving steady translation of the primary and secondary platforms in the X, Y, and Z directions. When the self-locking gripper does not need to move a large distance, the first flexible cables can remain stationary. The main controller drives the second motor and the electric telescopic rod to operate, the second drum rotates, and the four second flexible cables are wound and released in coordination, thereby achieving steady translation of the secondary platform in the X, Y, and Z directions over a small distance.

[0078] 4. The principle of a self-locking gripper: such as Figure 22 As shown, taking the initial state where the self-locking rod is located in the first stop groove as an example, the gripper is in a clamped state initially. When the gripper needs to release the blade to be ground, the four sets of second flexible cables retract simultaneously. At this time, the second flexible cables drive the slider to slide along the slide groove towards the self-locking cylinder by pushing the pulley, simultaneously driving the strip push rod to move towards the self-locking cylinder. During the movement, the strip push rod first contacts the inclined sliding surface on the helical teeth, and then continues to push along the direction of the inclined sliding surface until the self-locking cylinder rotates. The self-locking rod disengages from the first stop groove and enters the second stop groove. At this time, the gripper is in a state of releasing the blade to be ground. Repeating the action of pushing the strip push rod allows the self-locking rod to alternately engage with the first stop groove and the second stop groove. When the self-locking rod engages with the first stop groove, the self-locking cylinder cannot rotate and thus self-locks, and the gripper is in a state of clamping the blade to be ground. When the self-locking rod engages with the second stop groove, the gripper is in a state of releasing the blade to be ground.

[0079] 5. Degrees of freedom of the hoisting mechanism: The hoisting mechanism of the present invention has six degrees of freedom, specifically the translational degrees of freedom in the X, Y, and Z directions controlled by the primary platform control mechanism, the translational degrees of freedom in the X, Y, and Z directions further controlled by the electric telescopic rod and gripper attitude control mechanism of the secondary platform, the rotational degrees of freedom about the Z-axis controlled by the auxiliary gripper, and the rotational degrees of freedom about the X and Y axes controlled by the second flexible cable.

[0080] 6. The working process of this invention is as follows:

[0081] During operation, the self-locking gripper is first quickly moved to the designated position by the primary platform control mechanism, while the second flexible cable remains slack. Next, the second flexible cable tightens at the first stage, and the electric telescopic rod extends, controlling the self-locking gripper to move above the conveyor belt. Then, the second flexible cable group tightens at the second stage, triggering the self-locking gripper to work and clamp the root end of the blade to be polished. Next, the electric telescopic rod retracts, and the secondary platform rises above the auxiliary gripper, where the pneumatic gripper clamps the blade end of the blade to be polished. Finally, the robotic arm of the polishing mechanism assists in the polishing process. During polishing, the auxiliary gripper and the second flexible cable group can control the posture of the blade to be polished, ensuring that the variable curvature surface of the blade is always in the optimal polishing position, ultimately achieving complete polishing of the aerospace blade.

[0082] Specifically, the first flexible cable is connected to the primary platform via the winding and unwinding of the first drum and the guidance of the first guide pulley group. Under normal circumstances, it enables the primary platform to achieve three translational degrees of freedom, thereby driving the secondary platform and the self-locking gripper to move synchronously. When the secondary platform reaches the designated position, the second flexible cable, through the winding and unwinding of the second drum and the extension and retraction of the electric telescopic rod, controls the translation of the mounting plate along the X, Y, and Z directions and its rotation around the X and Y axes within a certain angular range. This allows the self-locking gripper to clamp the root end of the blade to be ground from the conveyor belt and move it above the auxiliary gripping mechanism. After the pneumatic gripper clamps the lower end of the blade to be ground, the grinding mechanism grinds the blade. During the grinding process, the pneumatic gripper can be retracted and extended at any time, facilitating the gripper attitude control mechanism to control the rotation of the blade to be ground around the X and Y axes, adjusting the blade to the optimal grinding posture, and rotating it along the Z axis within a certain angle in accordance with the blade shape. The grinding steps are repeated continuously to complete all-round grinding. Finally, the polished blades are returned to the conveyor belt, and the above process is repeated.

[0083] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A rigid-flexible coupling collaborative aerospace blade grinding robot, characterized in that: It includes a frame (1) with a hoisting mechanism arranged therein. An auxiliary gripper (12), a conveyor belt (13) and a grinding mechanism (14) are provided at the bottom of the frame (1); the hoisting mechanism includes a first-level platform (2), a second-level platform (3) and a self-locking gripper (4) arranged successively from top to bottom. The first-level platform (2) is connected to the top plate (11) of the frame through a guiding rod (21), and a compression spring (22) is sleeved on the guiding rod (21). The first-level platform (2) is connected to the second-level platform (3) through an electric telescopic rod (91) in a variable stiffness mechanism (9). The second-level platform (3) is fixed to the mounting plate (41) at the top of the self-locking gripper (4). The first-level platform (2) is connected to the first drum (71) in the first-level platform control mechanism (7) through a first flexible cable (5). The self-locking gripper (4) is connected to the second drum (81) in the gripper attitude control mechanism (8) through a second flexible cable (6). The rubber jaws (486) in the self-locking gripper (4) are used to grip the root end of the blade (10) to be polished, and the pneumatic jaws (125) in the auxiliary gripper (12) are used to grip the blade end of the blade (10) to be polished; The self-locking gripper (4) includes a mounting plate (41) fixed to the second-level platform (3). Four flexible clamping modules with the same structure and arranged in a "field" shape are fixed to the lower surface of the mounting plate (41). The four flexible clamping modules are rotated 90° in sequence; The flexible clamping module includes a housing (42) and two self-locking cylinders (43) arranged in parallel in the housing (42). The self-locking cylinder (43) is a hollow columnar body with one end closed and the other end open. Three straight first stopping grooves (431) are arranged along the circumferential direction of the outer wall of the self-locking cylinder (43). The setting direction of the first stopping groove (431) coincides with the axial direction of the self-locking cylinder (43). Two continuous helical teeth (433) are arranged between adjacent two groups of first stopping grooves (431). A second stopping groove (432) is formed between the two groups of helical teeth (433). The helical teeth (433) are composed of a vertical surface (4331) and an inclined sliding surface (4332). In the initial state, the self-locking rod (4222) arranged inside the housing (42) is engaged with any one of the three groups of first stopping grooves (431) or the three groups of second stopping grooves (432); The flexible clamping module further includes a flexible cable guiding block (44), a fixed pulley (45), a pushing pulley (46) and a flexible cable fixing block (47) located on the upper surface of the housing (42) and cooperating with the second flexible cable (6). The second flexible cable (6) passes through the guiding hole in the flexible cable guiding block (44) and then winds around the fixed pulley (45), the pushing pulley (46) in sequence and is fixed to the flexible cable fixing block (47); The flexible clamping module further includes a gripper assembly (48), which includes a first cylindrical rod (481) vertically penetrating the housing (42). The orientation of the first cylindrical rod (481) coincides with the axial direction of the self-locking cylinder (43). Two sets of the first cylindrical rods (481) are arranged side by side. One end of the first cylindrical rod (481) outside the housing (42) is fixed to the upright plate (482), and the other end of the first cylindrical rod (481) inside the housing (42) is fixed to the first circular connecting plate (483). The plate (483) is connected to the closed end of the self-locking cylinder (43) through a one-way thrust ball bearing (484). A first rebound spring (485) is sleeved on the first cylindrical rod (481) inside the housing (42). The two ends of the first rebound spring (485) are fixedly connected to the first circular connecting plate (483) and the inner wall of the housing (42) respectively. A rubber claw (486) is connected to the bottom of the upright plate (482). The rubber claw (486) is located below the housing (42), and the rubber claws (486) in the four sets of flexible clamping modules are arranged together to form a clamping part. The flexible clamping module further includes a pushing component (49), which includes an I-shaped slider (491). The slider (491) cooperates with a groove (4221) in the housing (42), and the upper surface of the slider (491) is fixed to the axle of the pushing pulley (46). Pushing members are provided on the left and right sides of the slider (491). The pushing members include an arc-shaped connecting rod (492) fixed to the slider (491) and a strip-shaped push rod (493) fixed to the arc-shaped connecting rod (492). The sliding direction of the slider (491) and the setting direction of the strip-shaped push rod (493) are both consistent with the axial direction of the self-locking cylinder (43). The end of the strip-shaped push rod (493) is a bevel. The strip-shaped push rod (493) is connected to the self-locking cylinder (43). The rods (4222) are arranged parallel to each other and are tangent to each other. The release and retraction of the second flexible cable (6) causes the slider (491) to slide along the direction defined by the slide groove (4221). The strip push rod (493) abuts against or separates from the inclined sliding surface (4332) on the self-locking cylinder (43) during the sliding of the slider (491). The push assembly (49) also includes a second cylindrical rod (494) and a second rebound spring (495). One end of the second cylindrical rod (494) is vertically connected to the axle of the push pulley (46). The other end of the second cylindrical rod (494) is provided with a second circular connecting plate (496). The two ends of the second rebound spring (495) are respectively fixed to the second circular connecting plate (496) and the baffle (4213) provided on the housing (42).

2. The rigid-flexible coupling collaborative aerospace blade grinding robot according to claim 1, characterized in that: The shell (42) is square in shape and is formed by the combination of a first shell (421) and a second shell (422) arranged in the vertical direction; the flexible cable guide block (44) is located at one corner of the upper surface of the first shell (421), and the other three corners of the upper surface of the first shell (421) are respectively provided with columns (423) that are bolted to the mounting plate (41). The flexible cable guide blocks (44) in the four sets of flexible clamping modules are respectively located at the four corners of the mounting plate (41); The first housing (421) is provided with a first groove (4211) that cooperates with the axle of the push pulley (46) and a second groove (4212) that cooperates with the second rebound spring (495). The first groove (4211) and the second groove (4212) are connected. The baffle (4213) is fixed at the end of the second groove (4212) away from the first groove (4211). The first housing (421) and the second housing (422) are respectively provided with semi-circular grooves for accommodating self-locking cylinders (43) on their mating end faces. The sliding groove (4221) is provided on the second housing (422) and is located in the middle of the two sets of semi-circular grooves of the second housing (422). The bottom of the semi-circular groove in the second housing (422) is provided with a self-locking rod (4222). The arc-shaped connecting rod (492) is fitted to the semi-circular groove of the second housing (422).

3. The rigid-flexible coupling collaborative aerospace blade grinding robot according to claim 1, characterized in that: The primary platform control mechanism (7) includes a first drum (71), a first motor (72) that drives the first drum (71) to rotate, and a first guide pulley group that cooperates with the first flexible cable (5). The first guide pulley group includes a first guide pulley (73) fixed on the upper surface of the frame top plate (11) and a second guide pulley (74) fixed on the lower surface of the frame top plate (11). The first drum (71) and the first motor (72) are both fixed on the upper surface of the frame top plate (11) through the first drum bracket (75). One end of the first flexible cable (5) is fixed to the first drum (71), and the other end of the first flexible cable (5) passes through the first guide pulley (73) and the second guide pulley (74) in sequence before being fixed to the primary platform (2). The primary platform (2) is a triangular platform. The first flexible cable (5) and the primary platform control mechanism (7) are each set in three groups. The three groups of the first flexible cable (5) are fixed to the three sides of the primary platform (2). The three groups of the primary platform control mechanism (7) are arranged in an equilateral triangle shape at the center of the frame top plate (11). The three groups of the first flexible cable (5) are all double cable structures arranged in parallel.

4. The rigid-flexible coupling collaborative aerospace blade grinding robot according to claim 1, characterized in that: One end of the guide rod (21) is connected to the center of the frame top plate (11) through a rubber sleeve (211), and the other end of the guide rod (21) is connected to the center of the first platform (2) through a ball joint. The two ends of the compression spring (22) are fixed to the lower surface of the frame top plate (11) and the upper surface of the first platform (2) respectively. When the first drum (71) drives the first flexible cable (5) to retract, the guide rod (21) moves up and down inside the rubber sleeve (211), and the compression spring (22) is always in a compressed state.

5. The rigid-flexible coupling collaborative aerospace blade grinding robot according to claim 1, characterized in that: The variable stiffness mechanism (9) includes an electric telescopic rod (91) connecting the primary platform (2) and the secondary platform (3). The seat end of the electric telescopic rod (91) is connected to the center of the primary platform (2) through a first ball joint (92), and the rod end of the electric telescopic rod (91) is connected to the center of the secondary platform (3) through a second ball joint (93). The variable stiffness mechanism (9) also includes a square bushing (94) and a spring assembly connecting the square bushing (94) and the secondary platform (3). The square bushing (94) is sleeved on the seat of the electric telescopic rod (91) and fixedly connected to the seat. The spring assembly includes four sets of springs (95). One end of each set of springs (95) is connected to the four sides of the square bushing (94), and the other end of each set of springs (95) is connected to the secondary platform (3). The square bushing (94) has a semi-circular buckle (941) at the center of each of its four sides that cooperates with the spring (95). The secondary platform (3) has four sets of lifting rings (31) that cooperate with the spring (95). The position of the lifting ring (31) corresponds to the position of the semi-circular buckle (941), and the center point of the four sets of semi-circular buckles (941) is collinear with the center point of the four sets of lifting rings (31).

6. The rigid-flexible coupling collaborative aerospace blade grinding robot according to claim 1, characterized in that: The auxiliary clamp (12) includes a base (121) and a rotating seat (122) rotatably connected above the base (121). The base (121) is equipped with a third motor (123) that drives the rotating seat (122) to rotate. The upper surface of the rotating seat (122) is provided with a mounting groove (124) along its radial direction. Pneumatic grippers (125) are symmetrically provided on the two side walls of the mounting groove (124).

7. The rigid-flexible coupling collaborative aerospace blade grinding robot according to claim 1, characterized in that: The gripper attitude control mechanism (8) includes a second drum (81), a second motor (82) that drives the second drum (81) to rotate via a synchronous belt pulley mechanism, a reversing pulley group and a second guide pulley group that cooperate with the second flexible cable (6), and a variable stiffness pulley mechanism (84) for adjusting the stiffness of the second flexible cable (6). The second drum (81) is fixed to the upper surface of the frame top plate (11) by a mounting plate (83). The drum is a non-uniform diameter drum, comprising a large-diameter drum section (811) and a small-diameter drum section (812) coaxially arranged, wherein: the large-diameter drum section (811) is fixed to the second flexible cable (6), and the small-diameter drum section (812) is fixed to the variable stiffness flexible cable (841) in the variable stiffness pulley mechanism (84). The second flexible cable (6) and the variable stiffness flexible cable (841) are wound in opposite directions, and the diameter of the second flexible cable (6) is larger than the diameter of the variable stiffness flexible cable (841).

8. The rigid-flexible coupling collaborative aerospace blade grinding robot according to claim 7, characterized in that: The reversing pulley assembly includes a first reversing pulley (85), a second reversing pulley (86) and a third reversing pulley (87) fixed on the upper surface of the mounting plate (83). The second guide pulley assembly includes a third guide pulley (88) fixed on the upper surface of the mounting plate (83) and a fourth guide pulley (89) fixed on the lower surface of the frame top plate (11). The variable stiffness pulley mechanism (84) is disposed between the first reversing pulley (85) and the second reversing pulley (86). The variable stiffness pulley mechanism (84) includes a variable stiffness flexible cable (841), a variable stiffness sliding pulley (842), a rebound spring (843), a first spring fixing seat (844) and a second spring fixing seat (845) fixed to both ends of the rebound spring (843). One end of the variable stiffness flexible cable (841) is fixed to the small diameter drum section (812) of the second drum (81), and the other end of the variable stiffness flexible cable (841) is fixed to the wheel axle of the variable stiffness sliding pulley (842). One end of the second flexible cable (6) is fixed to the large diameter drum section (811) of the second drum (81), and the other end of the second flexible cable (6) passes sequentially through the first reversing pulley (85), the variable stiffness sliding pulley (842), the second reversing pulley (86), the third reversing pulley (87), the third guide pulley (88), and the fourth guide pulley (89) before being connected to the self-locking clamp (4).

9. The rigid-flexible coupling collaborative aerospace blade grinding robot according to claim 8, characterized in that: The mounting plate (83) is provided with a groove (831) for accommodating a variable stiffness sliding pulley (842). The width of the groove (831) matches the diameter of the variable stiffness sliding pulley (842). A through groove (832) is provided at the bottom of the groove (831) along its length. The axle of the variable stiffness sliding pulley (842) passes through this through groove (832) and is fixedly connected to the second spring fixing seat (845). The first spring fixing seat (844) is on the lower surface of the mounting plate (83). The opening and closing of the variable stiffness flexible cable (841) causes the variable stiffness sliding pulley (842) to slide in the groove (831) to ensure the stiffness of the second flexible cable (6). A protective cover (833) is provided above the mounting plate (83). The top plate (11) of the frame is provided with a notch for the avoidance spring (843), the first spring fixing seat (844), and the second spring fixing seat (845).

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