Multi-angle workbench based on cotangent transformation

Abstract

The multi-angle workbench based on cotangent transformation comprises a workbench base, a workpiece table mounting base is fixed to one side of the surface of the workbench base through cooperation of bolts and T-shaped protruding blocks, and a horizontal driving assembly is arranged in the center of the surface of the workpiece table mounting base; the horizontal driving assembly comprises a workpiece bearing table fixedly welded to the workpiece table mounting base, a first driving motor is mounted at one end of the workpiece bearing table, the output end of the first driving motor penetrates through the workpiece bearing table and is connected with a transmission lead screw through a coupler, and the outer side of the transmission lead screw is in threaded connection with a lead screw nut base; through collaborative optimization of a cotangent transformation algorithm and a mechanical structure, the technical bottlenecks of a multi-angle workbench in the aspects of dynamic precision, hinge rigidity, error suppression and self-adaptive clamping are overcome, and the precision, efficiency and reliability of complex workpiece machining are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent motion control of multi-functional workbenches for precision machine tools, and specifically to a multi-angle workbench based on cotangent transformation. Background Technique

[0002] As a key device in the fields of precision machining, automated assembly, inspection and measurement, etc., the core function of the multi-angle workbench is to provide high-precision multi-degree-of-freedom position adjustment to meet the processing or positioning requirements of complex workpieces. Currently, the multi-angle workbenches on the market mainly rely on mechanical transmission and servo control methods to achieve angle adjustment.

[0003] In the fields of precision machining, automated assembly, and optical inspection, etc., the multi-angle workbench needs to simultaneously meet the requirements of high-precision positioning and multi-degree-of-freedom flexible adjustment. However, there are four key technical bottlenecks in the existing technology: First, the coordination between angle adjustment and position compensation is insufficient. The traditional workbench uses a step-by-step control method, resulting in low efficiency and significant cumulative errors. The lack of a real-time dynamic compensation mechanism makes it difficult to adapt to high-dynamic-precision scenarios; Second, there is a contradiction between rigidity and flexibility in the multi-degree-of-freedom articulated structure. The existing spherical articulated components have defects such as large return clearance and insufficient locking rigidity due to single-point contact or spring preloading methods. They can neither balance large-angle adjustment and high-load stability nor face the problem of accuracy deterioration caused by friction loss and center drift at the articulated part; Third, the non-linear error of the transmission chain is difficult to effectively suppress. The backlash error of the worm and worm gear pair and the elastic deformation of the lead screw drive jointly lead to a decrease in the end positioning accuracy. The existing compensation methods not only have limited correction effects but also increase the system complexity; Fourth, the self-adaptability of the clamping mechanism is insufficient. The rigid clamping of the traditional fixture is likely to cause damage to the workpiece surface or clamping deformation, especially when dealing with shaped curved surface workpieces.

[0004] Therefore, a multi-angle workbench based on cotangent transformation is proposed to solve the problems mentioned above. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-angle workbench based on cotangent transformation to solve the problems in the above background technique that there are significant technical defects in the current multi-angle workbench in terms of angle and displacement coordinated control, articulated structure rigidity, transmission chain error compensation, and clamping self-adaptability, which seriously restrict its performance in high-precision multi-degree-of-freedom adjustment applications.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A multi-angle workbench based on cotangent transformation, including a workbench base, On one side of the surface of the workbench base, a workpiece table mounting seat is fixed by bolts in cooperation with T-shaped bumps, and a horizontal drive assembly is provided at the center of the surface of the workpiece table mounting seat; The horizontal driving assembly includes a workpiece bearing table welded and fixed to the workpiece table mount. One end of the workpiece bearing table is equipped with a first driving motor, and its output end penetrates the workpiece bearing table and is connected with a transmission lead screw through a coupling. A lead screw nut seat is threadedly connected to the outside of the transmission lead screw. The top of the lead screw nut seat is fixedly connected with a linkage block. The inside of the linkage block is slidably sleeved with a linkage guide rod fixed at both ends to the workpiece bearing table. The two ends of the top side of the linkage block penetrate through the table body chute on the workpiece bearing table through connecting columns and are fixedly connected with a connecting seat. A spherical hinge assembly is arranged on the surface of the connecting seat; The spherical hinge assembly includes a hinge base fixed to the center of the surface of the connecting seat by bolts. An articulated column is rotatably connected inside the hinge base. The top of the articulated column is fixedly connected with a spherical hinge piece. A plurality of card slots are evenly distributed on the outer surface of the spherical hinge piece. Steel balls are rollingly embedded in each card slot. The outside of the steel balls is fitted with a matching card slot on the inner wall of the external connecting piece. A rotating assembly is arranged at one end of the external connecting piece; The rotating assembly includes a transmission connecting rod fixedly connected to one end of the external connecting piece. The transmission connecting rod is circumferentially fixed to a transmission worm gear inside a rotating joint housing through a flat key. The rotating joint housing is supported on a support seat through a bearing. The support seat is fixed to the workbench base through bolts and a T-shaped convex block. A second driving motor installed on the outer side wall of the rotating joint housing drives the transmission worm gear to rotate through a transmission worm. A clamping assembly is arranged on the outer side of the transmission connecting rod near one end of the rotating joint housing; The clamping assembly includes a clamping base fixedly connected to one end of the transmission connecting rod. An operating rod is rotatably installed on the side wall of the clamping base. The inner end of the operating rod is fixedly connected with a bidirectional threaded rod. The left and right threaded sections of the bidirectional threaded rod are symmetrically engaged with threaded sleeves respectively. The top of each threaded sleeve is vertically fixedly connected with a sliding sleeve. The sliding sleeve is slidably sleeved on a guide rod fixed at both ends on the clamping base. And the top of the sliding sleeve is fixedly connected with a clamping housing that can slide along the clamping base. Inside the clamping housing, a first clamping block, a second clamping block, a third clamping block and a fourth clamping block are sequentially connected through a multi-stage rotating pair. The working surface of the fourth clamping block contacts the workpiece body, and the reference end face of the workpiece body abuts against the positioning surface of the clamping base.

[0007] Preferably, the table body chute of the workpiece bearing table is a linear through groove, and its length direction is parallel to the axis of the transmission lead screw. The groove width forms a clearance fit with the diameter of the connecting column.

[0008] Preferably, the number of card slots of the spherical hinge piece is eight, and the cross section of the card slot is arc-shaped.

[0009] Preferably, in the multi-stage rotating pair of the clamping assembly, the rotation axes between adjacent clamping blocks are arranged orthogonally, and the working surface of the fourth clamping block is provided with a polyurethane anti-slip layer.

[0010] Preferably, the transmission lead screw of the horizontal drive assembly is a ball screw, and its lead accuracy grade reaches ISOP3 level.

[0011] Preferably, the module of the transmission worm and the transmission worm gear is 2 - 4 mm, the transmission ratio is 15:1 - 20:1, and the contact spot area of the worm and worm gear pair is not less than 60% of the tooth surface.

[0012] Preferably, the control system of the horizontal drive assembly and the rotating assembly integrates a cotangent transformation algorithm module, and this module is configured as follows: when the workpiece angle adjustment amount θ satisfies 0° < θ < 90°, calculate in real time according to θ: The displacement compensation value L of the transmission lead screw = H · cotθ, where H is the vertical height constant of the hinge assembly; The rotation angle compensation value α of the transmission worm = k · θ, where k is the transmission ratio of the transmission worm gear to the transmission worm; The control system controls the coordinated movement of the horizontal drive assembly and the rotating assembly according to L and α.

[0013] Preferably, the execution logic of the cotangent transformation algorithm module includes: When it is detected that the real - time deflection angle of the spherical hinge assembly exceeds the set threshold, automatically trigger the displacement compensation calculation; Convert the calculated displacement compensation value into a pulse control signal for the first drive motor; Synchronously generate a worm rotation angle control instruction corresponding to the angle adjustment amount.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This multi - angle workbench based on cotangent transformation, through the collaborative optimization of the cotangent transformation algorithm and the mechanical structure, overcomes the technical bottlenecks in dynamic accuracy, hinge rigidity, error suppression, and adaptive clamping of the multi - angle workbench, and significantly improves the accuracy, efficiency, and reliability of complex workpiece processing. The specific content is as follows: 1. High - precision dynamic collaborative control By integrating the cotangent transformation algorithm module, an accurate mathematical model of horizontal displacement and rotation angle is constructed, realizing the intelligent linkage control of the horizontal drive assembly and the rotating assembly; this technical solution can automatically coordinate the non - linear relationship between displacement and angle, effectively solve the problem of error accumulation existing in the traditional step - by - step adjustment method, significantly improve the accuracy of workpiece angle adjustment, and is particularly suitable for precision machining application scenarios with strict requirements for dynamic accuracy; 2. Optimized spherical hinge structure, balancing flexibility and stability An innovative design of an arc-section card slot with eight evenly distributed slots and rolling contact of steel balls is adopted, which significantly increases the number of contact points compared with the traditional structure and effectively improves the stress distribution; through the multi-directional constraint cooperation between the steel balls and the card slots of the external connecting parts, while ensuring the large-angle adjustment ability, the axial rigidity and stability of the structure are greatly improved, and the wear problem and the center drift defect existing in the traditional hinge device are successfully solved; 3. Comprehensive suppression of transmission chain error A high-precision ball screw and an optimized worm and worm gear transmission system are adopted, combined with real-time compensation control of the cotangent transformation algorithm, effectively suppressing the non-linear error in the mechanical transmission process; this technical solution can significantly reduce the backlash of the transmission system and compensate for the influence of mechanical deformation on the positioning accuracy, thus achieving high repeat positioning accuracy at the end of the workbench; 4. Adaptive clamping and multi-degree-of-freedom adjustment ability The clamping component adopts a symmetrical sliding sleeve structure driven by a bidirectional threaded rod, combined with multi-stage orthogonal rotary clamping blocks, to achieve adaptive clamping of workpieces with different curvature surfaces; through the unique design of introducing a polyurethane anti-slip layer and a floating fourth clamping block, while ensuring clamping stability, the surface of the workpiece is effectively protected, and the clamping posture and the machining reference are kept precisely unified; this structure significantly improves the adaptability and reliability of the clamping system; 5. Modularity and scalability The modular design concept is adopted. Through the combined structure of T-shaped convex block installation interfaces, standardized transmission connecting rods and replaceable clamping components, the flexible configuration and rapid adaptation ability of the workbench system are realized; at the same time, the open control system architecture supports the continuous expansion of algorithm functions, enabling the cotangent transformation module to integrate more advanced compensation functions, significantly enhancing the adaptability and upgrade potential of the equipment. Description of the drawings

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a sectional view of the internal structure of the workpiece bearing table of the present invention; Figure 3 It is a schematic diagram of the structure of the spherical articulated external connection part of the present invention; Figure 4 It is a schematic diagram of the exploded structure of the lifting spherical hinge assembly of the present invention; Figure 5 It is a schematic diagram of the internal structure of the transmission connecting rod and the rotating joint of the present invention; Figure 6 It is a schematic sectional view of the internal transmission of the clamping base of the present invention; Figure 7 It is a schematic sectional view of the internal structure of the clamping housing of the present invention; Figure 8This is a schematic top view sectional structure diagram of the clamping housing of the present invention.

[0016] In the figure: 1, workbench base; 2, workpiece table mounting seat; 3, horizontal drive assembly; 301, workpiece carrier table; 302, first drive motor; 303, transmission lead screw; 304, lead screw nut seat; 305, linkage block; 306, linkage guide rod; 307, connecting column; 308, table body chute; 309, connecting seat; 4, spherical hinge assembly; 401, hinge base; 402, hinge column; 403, spherical hinge; 404, card slot; 405, steel ball; 406, external connecting member; 5, rotating assembly; 501, transmission connecting rod; 502, flat key; 503, rotating joint housing; 504, support seat; 505, second drive motor; 506, transmission worm; 507, transmission worm gear; 6, clamping assembly; 601, clamping base; 602, operating rod; 603, bidirectional threaded rod; 604, threaded sleeve; 605, sliding sleeve; 606, guide rod; 607, clamping housing; 608, first clamping block; 609, second clamping block; 610, third clamping block; 611, fourth clamping block; 612, workpiece body. Specific embodiments

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] Please refer to Figure 1-8 , the present invention provides a technical solution: a multi-angle workbench based on cotangent transformation, including a workbench base 1. One side of the surface of the workbench base 1 is fixed with a workpiece table mounting seat 2 through cooperation with a T-shaped convex block by bolts. The center of the surface of the workpiece table mounting seat 2 is provided with a horizontal drive assembly 3; the horizontal drive assembly 3 includes a workpiece carrier table 301 welded and fixed to the workpiece table mounting seat 2. One end of the workpiece carrier table 301 is provided with a first drive motor 302, and its output end penetrates through the workpiece carrier table 301 and is connected with a transmission lead screw 303 through a coupling. The outer side of the transmission lead screw 303 is threadedly connected with a lead screw nut seat 304. The top end of the lead screw nut seat 304 is fixedly connected with a linkage block 305. The inside of the linkage block 305 is slidably sleeved with a linkage guide rod 306 fixed at both ends to the workpiece carrier table 301. Both ends of the top side of the linkage block 305 penetrate through the table body chute 308 on the workpiece carrier table 301 through a connecting column 307 and are fixedly connected with a connecting seat 309. The surface of the connecting seat 309 is provided with a spherical hinge assembly 4; The workbench base 1 and the workpiece table mounting seat 2 adopt a modular connection method of high-strength bolts and T-shaped bumps, which is not only convenient for quick disassembly, installation and maintenance, but also its special cross-section design can effectively resist external forces, ensuring stable positioning accuracy under various working conditions; the workpiece carrying table 301 is precision machined from high-quality cast iron material. After special welding process and heat treatment process, its structural strength and dynamic characteristics are significantly improved; the first driving motor 302 selects a high-performance servo motor (preferably Panasonic MINAS A6 series), which is connected to a high-precision ball screw through a precision coupling, and cooperates with a specially treated guide rod structure to achieve excellent transmission performance and rigidity performance; the connecting column 307 and the table body chute 308 adopt a precision fit design, and the connecting column 307 with special surface treatment ensures high linear accuracy during long-stroke movement; the key components adopt advanced welding process, stress relief process and surface treatment process, making the workbench have extremely high movement accuracy and service life; The spherical hinge assembly 4 includes a hinge base 401 fixed to the center of the surface of the connecting seat 309 by bolts. A hinge column 402 is rotatably connected inside the hinge base 401. A spherical hinge piece 403 is fixedly connected to the top end of the hinge column 402. A plurality of card slots 404 are evenly distributed on the outer surface of the spherical hinge piece 403. Steel balls 405 are rollingly fitted in each card slot 404. The outer sides of the steel balls 405 are fitted to the matching card slots 404 on the inner wall of the external connecting member 406. A rotating assembly 5 is provided at one end of the external connecting member 406; The hinge base 401 made of high-strength alloy material forms a rigid connection with the spherical hinge piece 403 treated with special steel. With the rolling contact design of the precision machined card slot 404 structure and high-quality steel balls 405, the assembly has both excellent movement performance and load-bearing capacity; through strict control of machining tolerances and assembly accuracy requirements, the movement accuracy and stability of the assembly within a large-angle rotation range are ensured; compared with the traditional hinge structure, this design effectively reduces the friction coefficient and disperses the contact stress through the rolling contact of multiple steel balls 405, improving the load capacity. At the same time, the damping characteristics of the steel balls 405 can absorb machining vibrations to ensure the precision machining quality; The rotating assembly 5 includes a transmission connecting rod 501 fixedly connected to one end of the external connecting member 406. The transmission connecting rod 501 is circumferentially fixed to a transmission worm gear 507 inside a rotating joint housing 503 through a flat key 502. The rotating joint housing 503 is supported on a support seat 504 through bearings. The support seat 504 is fixed to the workbench base 1 through bolts and T-shaped bumps. A second driving motor 505 installed on the outer side wall of the rotating joint housing 503 drives the transmission worm gear 507 to rotate through a transmission worm 506. A clamping assembly 6 is provided on the outer side of the transmission connecting rod 501 near one end of the rotating joint housing 503; The transmission connecting rod 501 is made of 40Cr alloy steel that has been quenched and tempered, and is rigidly connected to the external connection piece 406 through interference fit and positioning stop. The flat key 502 cooperates with the precisely machined keyway to achieve reliable circumferential fixation of the transmission worm wheel 507 to avoid relative sliding. The rotating joint housing 503 is cast and finely machined with HT250 cast iron, and is internally configured with high-precision bearings to support the transmission connecting rod 501 to ensure the smoothness and load-bearing capacity of the rotational motion. The support seat 504 is fixed to the workbench base 1 by bolts and T-slot structure, and has both modular installation convenience and overall rigidity. The second drive motor 505 is driven by a worm gear pair (transmission worm 506 and transmission worm wheel 507), and is made of high-quality materials and precision machining (such as 20CrMnTi carburized and quenched worm, ZCuSn10P1 tin bronze worm wheel) to achieve a high reduction ratio, self-locking function and large torque output. The clamping assembly 6 includes a clamping base 601 fixedly connected to one end of the transmission connecting rod 501, an operating rod 602 is rotatably installed on the side wall of the clamping base 601, a bidirectional threaded rod 603 is fixedly connected to the inner end of the operating rod 602, and the left and right threaded sections of the bidirectional threaded rod 603 are symmetrically meshed with threaded sleeves 604, and a sliding sleeve 605 is vertically fixedly connected to the top of each threaded sleeve 604. The sliding sleeve 605 is slidably sleeved on a guide rod 606 fixed on both ends of the clamping base 601, and the top of the sliding sleeve 605 is fixedly connected to a clamping shell 607 that can slide along the clamping base 601, and the first clamping block 608, the second clamping block 609, the third clamping block 610 and the fourth clamping block 611 are sequentially connected in the clamping shell 607 through a multi-stage rotating pair, the working surface of the fourth clamping block 611 is in contact with the workpiece body 612, and the reference end surface of the workpiece body 612 abuts against the positioning surface of the clamping base 601; The bidirectional threaded rod 603 can be driven by rotating the operating rod 602 to achieve rapid clamping and loosening, thereby improving work efficiency. The left-right thread design of the bidirectional threaded rod 603 enables the two threaded sleeves 604 to achieve synchronous reverse movement, thereby ensuring uniform distribution of the clamping force and avoiding deflection or uneven force on the workpiece. The precise sliding fit between the sliding sleeve 605 and the guide rod 606 ensures the linear motion stability of the clamping shell 607, reduces friction and shaking, and improves the clamping positioning accuracy. At the same time, the clamping structure composed of the multi-stage rotating pair can adapt to the surface shape of the workpiece body 612, thereby ensuring that the contact surface fits tightly, avoiding local stress concentration, and protecting the workpiece surface. The platform slide groove 308 of the workpiece bearing platform 301 is a straight through groove, the length direction of which is parallel to the axis of the transmission screw 303, and the groove width forms a clearance fit with the diameter of the connecting column 307; The frustum-shaped chute 308 adopts a straight through-slot design, and its length direction is strictly parallel to the axis of the transmission lead screw 303, ensuring that the linear motion trajectory of the lead screw nut seat 304 has no deviation, thereby guaranteeing the displacement accuracy of the linkage block 305 and the connecting seat 309 and reducing the motion interference caused by assembly errors; the slot width forms a clearance fit with the diameter of the connecting column 307, which can not only effectively limit the radial sway of the connecting column 307 in the chute, avoid transmission hysteresis caused by loosening, but also provide appropriate freedom of movement, reduce the sliding friction resistance, and extend the service life of the mechanism; The number of clamping grooves 404 of the spherical hinge 403 is eight, and the cross-section of the clamping groove 404 is arc-shaped; By arranging eight evenly distributed clamping grooves 404 on the spherical hinge 403, the force on the external connecting piece 406 can be evenly dispersed to each steel ball 405, avoiding local stress concentration, and significantly improving the bearing capacity and fatigue resistance of the hinge structure; the symmetrical layout of the eight clamping grooves 404 and the arc-shaped cross-section design enable the steel balls 405 to roll smoothly at any deflection angle, realizing flexible adjustment of multiple degrees of freedom, reducing sliding friction at the same time, and ensuring the smoothness and accuracy of angle adjustment; In the multi-stage rotating pairs of the clamping assembly 6, the rotation axes between adjacent clamping blocks are arranged orthogonally, and the working surface of the fourth clamping block 611 is provided with a polyurethane anti-slip layer; The design of the rotation axes between adjacent clamping blocks arranged orthogonally enables the clamping assembly 6 to achieve compound motion adjustment in three dimensions of X, Y, and Z, ensuring that the fourth clamping block 611 can adapt to the surface contour of workpieces with different shapes, realizing precise positioning and reliable clamping; the polyurethane anti-slip layer provided on the working surface of the fourth clamping block 611 has high friction coefficient and elastic deformation characteristics, which can not only effectively prevent the workpiece from slipping during processing, but also absorb vibration and impact through the elasticity of the material, protecting the surface of the workpiece body 612 from damage; The transmission lead screw 303 of the horizontal drive assembly 3 is a ball screw, and its lead accuracy grade reaches ISOP3 level; Adopting a ball screw with a high-precision grade as the transmission lead screw 303, its motion error is controlled within a very small range, ensuring that the displacement accuracy of the workpiece bearing table can meet the requirements of high-precision machining and achieving excellent positioning repeatability; The module of the transmission worm 506 and the transmission worm wheel 507 is 2 - 4 mm, the transmission ratio is 15:1 - 20:1, and the contact spot area of the worm and worm wheel pair is not less than 60% of the tooth surface; The design adopts a worm and worm gear pair with a medium module, achieving a compact structural layout while ensuring the transmission strength, enabling the transmission system to obtain an ideal torque transmission capacity within a limited space; adopting a larger transmission ratio design significantly improves the angular control accuracy of the output shaft, making the rotational positioning of the workbench more accurate and reliable, meeting the requirements of high-precision machining; ensuring that the contact area of the worm and worm gear pair reaches a high proportion, enabling the load to be evenly distributed in the tooth surface contact area, effectively reducing local stress concentration, and improving the service life of the transmission pair. The control system of the horizontal drive assembly 3 and the rotating assembly 5 integrates a cotangent transformation algorithm module, which is configured to: when the workpiece angle adjustment amount θ satisfies 0° < θ < 90°, calculate in real time according to θ: The displacement compensation value L of the transmission lead screw 303 = H · cotθ, where H is the vertical height constant of the hinge assembly 4; The angular compensation value α of the transmission worm 506 = k · θ, where k is the transmission ratio of the transmission worm gear 507 and the transmission worm 506; The control system controls the coordinated movement of the horizontal drive assembly 3 and the rotating assembly 5 according to L and α; By integrating the cotangent transformation algorithm module, intelligent linkage control of the horizontal drive assembly and the rotating assembly is realized, ensuring that the motion parameters of each actuator are automatically matched during the workpiece angle adjustment process, eliminating the cumulative error of traditional step-by-step adjustment; and based on the mathematical model, the displacement and angular compensation values are calculated in real time, enabling the system to automatically correct the motion parameters according to the actual adjustment angle, maintaining the accurate positioning of the machining reference, and improving the machining accuracy under complex angle conditions; at the same time, the real-time calculation function of the algorithm module ensures the synchronism of the movement of each drive assembly, avoiding motion interference or trajectory mutation caused by timing differences, and ensuring a smooth transition during the workpiece adjustment process. The execution logic of the cotangent transformation algorithm module includes: When it is detected that the real-time deflection angle of the spherical hinge assembly 4 exceeds the set threshold, the displacement compensation calculation is automatically triggered; Convert the calculated displacement compensation value into a pulse control signal for the first drive motor 302; Synchronously generate a worm angular control command corresponding to the angle adjustment amount; The execution logic of the cotangent transformation algorithm module realizes a high-precision conversion from theoretical calculation to actual motion through an intelligent real-time monitoring and automatic triggering mechanism; the system directly converts the compensation value calculated by the algorithm into a motor control signal by real-time detecting the deflection angle of the spherical hinge assembly 4 and intelligently judging the compensation timing, ensuring the seamless connection between the theoretical model and the actual execution; at the same time, a multi-axis coordinated control strategy is adopted to synchronously generate displacement and angular commands to ensure the accurate execution of complex space trajectories; the dynamic error correction function based on closed-loop feedback continuously optimizes the motion accuracy and effectively compensates for mechanical transmission errors.

[0019] Working principle: Before using the multi-angle workbench based on cotangent transformation, it is necessary to first check the overall condition of the device to ensure that it can work properly. According to Figure 1 - Figure 8 as shown in Working mechanism of the mechanical transmission system The horizontal drive assembly 3 drives the transmission lead screw 303 to rotate through the first drive motor 302, driving the lead screw nut seat 304 to move linearly along the linkage guide rod 306; the linkage block 305 precisely transfers the horizontal displacement to the connecting seat 309 through the clearance fit between the connecting column 307 and the table body chute 308; the spherical hinge assembly 4 adopts an eight-groove steel ball rolling structure. When the hinge column 402 is subjected to an external force, the spherical hinge 403 forms multi-directional rolling contact with the external connecting member 406 through the steel ball 405, achieving gapless deflection within a large angle range; the rotating assembly 5 converts the rotational motion of the second drive motor 505 into the axial rotation of the transmission link 501 through a worm and worm gear pair, and its high transmission ratio ensures the accuracy of angle adjustment; Mechanical force transmission of the clamping assembly The rotation of the operating rod 602 drives the bidirectional threaded rod 603 to drive the symmetric threaded sleeves 604 to move towards each other. Through the sliding pair constraint between the sliding sleeve 605 and the guide rod 606, the rotation is converted into the linear clamping force of the clamping housing 607; the multi-stage rotating pair decomposes the clamping force vector through an orthogonal hinge, making the polyurethane anti-slip layer of the fourth clamping block 611 generate uniformly distributed contact stress, ensuring the non-slip clamping of the workpiece body 612; Dynamic compensation principle of the cotangent transformation algorithm The control system continuously collects the deflection angle θ of the spherical hinge assembly 4 and performs the following calculations through an embedded processor: Horizontal displacement compensation amount: L = H·cotθ (H is a constant for the vertical height of the hinge assembly, and in this embodiment, it is taken as 120 mm); Rotation angle compensation amount: α = 18·θ (optimization coefficient based on a transmission ratio of 20:1); When θ belongs to (5°, 85°), the algorithm updates the compensation instruction at a period of 10 ms, and adjusts the pulse frequency of the first drive motor 302 and the rotation angle position of the second drive motor 505 through a PID controller to form a closed-loop control; Multi-degree-of-freedom coordinated control process a) System initialization stage: Each motion axis returns to the reference position; b) Angle setting stage: Input the target angle parameter, and the algorithm calculates the theoretical compensation amount; c) Motion execution stage: The horizontal axis and the rotation axis move synchronously to the target position; d) Dynamic correction stage: Adjust the compensation amount adaptively in real time through sensor feedback.

[0020] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. Multi-angle workbench based on cotangent transformation, including a workbench base (1), characterized in that: On one side of the surface of the workbench base (1), a workpiece table mounting seat (2) is fixed by bolts in cooperation with T-shaped bumps, and a horizontal driving assembly (3) is provided at the center of the surface of the workpiece table mounting seat (2); The horizontal driving assembly (3) includes a workpiece bearing table (301) welded and fixed to the workpiece table mounting seat (2). A first driving motor (302) is installed at one end of the workpiece bearing table (301), and its output end penetrates the workpiece bearing table (301) and is connected with a transmission lead screw (303) through a coupling. A lead screw nut seat (304) is threadedly connected to the outside of the transmission lead screw (303). The top end of the lead screw nut seat (304) is fixedly connected with a linkage block (305). A linkage guide rod (306) with both ends fixed to the workpiece bearing table (301) is slidably sleeved inside the linkage block (305). Both ends of the top side of the linkage block (305) penetrate through the table body chute (308) on the workpiece bearing table (301) through connecting columns (307) and are fixedly connected with a connecting seat (309). A spherical hinge assembly (4) is arranged on the surface of the connecting seat (309); The spherical hinge assembly (4) includes a hinge base (401) fixed to the center of the surface of the connecting seat (309) by bolts. A hinge column (402) is rotatably connected inside the hinge base (401). A spherical hinge piece (403) is fixedly connected to the top end of the hinge column (402). A number of clamping grooves (404) are evenly distributed on the outer surface of the spherical hinge piece (403). Steel balls (405) are rollingly embedded in each clamping groove (404). The outer sides of the steel balls (405) are fitted to the matching clamping grooves (404) on the inner wall of the external connecting piece (406). A rotating assembly (5) is arranged at one end of the external connecting piece (406); The rotating assembly (5) includes a transmission connecting rod (501) fixedly connected to one end of the external connecting piece (406). The transmission connecting rod (501) is circumferentially fixed to a transmission worm gear (507) inside a rotating joint housing (503) through a flat key (502). The rotating joint housing (503) is supported on a support seat (504) through bearings. The support seat (504) is fixed to the workbench base (1) by bolts in cooperation with T-shaped bumps. A second driving motor (505) installed on the outer side wall of the rotating joint housing (503) drives the transmission worm gear (507) to rotate through a transmission worm (506). A clamping assembly (6) is arranged on the outer side of the transmission connecting rod (501) near one end of the rotating joint housing (503); The clamping assembly (6) includes a clamping base (601) fixedly connected to one end of a transmission link rod (501). An operating rod (602) is rotatably mounted on the side wall of the clamping base (601). A bidirectional threaded rod (603) is fixedly connected to the inner end of the operating rod (602). Threaded sleeves (604) are symmetrically engaged with the left and right threaded sections of the bidirectional threaded rod (603) respectively. A sliding sleeve (605) is vertically and fixedly connected to the top of each threaded sleeve (604). The sliding sleeve (605) is slidably sleeved on a guide rod (606) fixed at both ends on the clamping base (601), and a clamping housing (607) that can slide along the clamping base (601) is fixedly connected to the top of the sliding sleeve (605). A first clamping block (608), a second clamping block (609), a third clamping block (610) and a fourth clamping block (611) are sequentially connected in the clamping housing (607) through a multi-stage rotating pair. The working surface of the fourth clamping block (611) contacts the workpiece body (612), and the reference end face of the workpiece body (612) abuts against the positioning surface of the clamping base (601).

2. The multi-angle workbench based on cotangent transformation according to claim 1, wherein: The table chute (308) of the workpiece bearing table (301) is a straight through groove, the length direction of which is parallel to the axis of the transmission lead screw (303), and the groove width forms a clearance fit with the diameter of the connecting column (307).

3. The multi-angle workbench based on cotangent transformation according to claim 1, characterized in that: The number of clamping grooves (404) of the spherical hinge member (403) is eight, and the cross section of the clamping groove (404) is arc-shaped.

4. The multi-angle workbench based on cotangent transformation according to claim 1, wherein: In the multi-stage rotating pair of the clamping assembly (6), the rotation axes between adjacent clamping blocks are orthogonally arranged, and a polyurethane anti-slip layer is provided on the working surface of the fourth clamping block (611).

5. The multi-angle workbench based on cotangent transformation according to claim 1, wherein: The transmission lead screw (303) of the horizontal drive assembly (3) is a ball screw, and its lead accuracy grade reaches ISOP3 level.

6. The multi-angle workbench based on cotangent transformation according to claim 1, wherein: The module of the transmission worm (506) and the transmission worm wheel (507) has a module of 2 - 4 mm, a transmission ratio of 15:1 - 20:1, and the contact spot area of the worm and worm wheel pair is not less than 60% of the tooth surface.

7. The multi-angle workbench based on cotangent transformation according to claim 1, characterized in that: The control system of the horizontal drive assembly (3) and the rotating assembly (5) is integrated with a cotangent transformation algorithm module, and this module is configured as follows: when the workpiece angle adjustment amount θ satisfies 0° < θ < 90°, calculate in real time according to θ: The displacement compensation value L of the transmission lead screw (303) = H · cotθ, where H is the vertical height constant of the hinge assembly (4); The rotation angle compensation value α of the transmission worm (506) = k · θ, where k is the transmission ratio of the transmission worm wheel (507) to the transmission worm (506); The control system controls the coordinated movement of the horizontal drive assembly (3) and the rotating assembly (5) according to L and α.

8. The multi-angle workbench based on cotangent transformation according to claim 7, characterized in that: The execution logic of the cotangent transformation algorithm module includes: When it is detected that the real-time deflection angle of the spherical hinge assembly (4) exceeds the set threshold, automatically trigger the displacement compensation calculation; Convert the calculated displacement compensation value into a pulse control signal of the first drive motor (302); Synchronously generate a worm rotation angle control instruction corresponding to the angle adjustment amount.

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