A new type of feed cabin based on nine-cable driven parallel mechanism for FAST

Abstract

The application discloses a new type of FAST feed source cabin based on a nine-cable driving parallel mechanism, which comprises a star-shaped frame, a plurality of sets of upper cable mechanisms, a plurality of sets of lower cable mechanisms, a feed source platform mechanism and a plurality of feed source receivers; the fixed end of the upper cable mechanism is fixedly installed on the upper part of the inner ring of the star-shaped frame, and the movable end of the upper cable mechanism is connected with a feed source platform in the feed source platform mechanism; the fixed end of the lower cable mechanism is fixedly installed on the lower part of the inner ring of the star-shaped frame, and the movable end of the lower cable mechanism is connected with an upper connecting plate in the feed source platform mechanism; the adjustment of the pitch angle of the feed source platform is realized by the winding and unwinding of the steel wire ropes in the upper and lower cable mechanisms. The application adopts a plurality of sets of cable mechanisms to realize the parallel driving of the feed source platform, so that the technical problems of the small adjustment range of the attitude angle and the small effective payload of the feed source cabin of the existing secondary fine adjustment mechanism are solved, and the total weight of the secondary fine adjustment mechanism can be reduced from 10.5 tons to 6 tons.

Description

Technical Field

[0001] This invention belongs to the field of fine-tuning mechanism technology, and in particular relates to a novel FAST feed cabin based on a nine-cable drive parallel mechanism. Background Technology

[0002] The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is the world's largest single-dish radio telescope, featuring three independent innovations: utilizing a natural karst depression in Guizhou as its site; an actively deformable reflector; and a lightweight feed support scheme based on a two-stage parallel robot.

[0003] The current FAST feed support system is as follows: a six-cable parallel robot pulls a 30-ton feed cabin. Inside the feed cabin, there is an AB two-axis steering mechanism (achieving ±18° rotation angle) and a six-bar Stewart parallel robot, which together achieve high-precision positioning of the feed at a height of more than 140m and within a range of 207m, with a positioning accuracy of 10mm.

[0004] The aforementioned AB rotating mechanism and Stewart parallel robot occupy approximately 10.5 tons of weight. Limited by the 30-ton safety threshold of the feed cabin, multiple new feed receiver devices cannot be installed simultaneously within the existing feed cabin, and the existing AB rotating mechanism is also difficult to respond to larger observation zenith angles. This invention relates to the upgrade and modification of the feed platform attitude adjustment and compensation mechanism within the feed cabin. Through this invention, a significant increase in the FAST observation angle can be achieved, and the weight of the feed cabin mechanism can be reduced to improve the feed cabin's effective payload capacity, providing technical support for enhancing the telescope's performance.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the general background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a novel FAST feed cabin based on a nine-cable-driven parallel mechanism. This new FAST feed cabin replaces the existing secondary fine-tuning mechanisms (AB pivot mechanism and six-bar Stewart parallel robot). Besides meeting the secondary fine-tuning requirements of the original feed platform's pose, it can also increase the pitch angle adjustment range from ±18° to over ±37°. More importantly, this invention also achieves lightweighting of the internal secondary fine-tuning mechanism, thereby significantly increasing the effective load of the feed cabin under the constraint of a cabin weight not exceeding 30 tons, meeting the requirement of simultaneously installing multiple feed receivers. Furthermore, by replacing the rigid drive mechanism with a flexible cable drive, this invention greatly simplifies the installation / disassembly and maintenance of the future feed platform and its auxiliary equipment, improving the maintainability of FAST.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention provides a novel FAST feed cabin based on a nine-cable-driven parallel mechanism, comprising: a star-shaped frame, several sets of upper cable mechanisms, several sets of lower cable mechanisms, a feed platform mechanism, and several feed receivers; wherein,

[0009] The fixed end of the upper cable mechanism is fixedly installed on the upper part of the inner ring of the star-shaped frame, and the movable end of the upper cable mechanism is connected to the feed platform in the feed platform mechanism; the fixed end of the lower cable mechanism is fixedly installed on the lower part of the inner ring of the star-shaped frame, and the movable end of the lower cable mechanism is connected to the upper connecting plate in the feed platform mechanism; the pitch angle of the feed platform is adjusted by the winding and unwinding of the steel wire ropes in the upper and lower cable mechanisms; the feed receiver is installed on the feed platform mechanism.

[0010] Furthermore, the new FAST feed cabin includes 6 sets of upper cable mechanisms and 3 sets of lower cable mechanisms; the winch mechanisms in the 6 sets of upper cable mechanisms are symmetrically distributed in pairs within the star-shaped frame, with every 3 sets evenly distributed relative to the center line of the star-shaped frame, and the plane where the center of the drum of each of the 6 sets of winch mechanisms is located is the upper surface of the base platform; the 6 sets of Hooke hinges in the upper cable mechanisms are symmetrically distributed in pairs, and the plane where the center of each of the 6 sets of Hooke hinges is located is the lower surface of the feed platform; the 3 sets of lower cable mechanisms are respectively installed at the symmetrical center positions of the two sets of upper cable mechanisms that are symmetrically distributed in pairs, and the plane determined by the rotation axis center of the 3 sets of anchor seats in the lower cable mechanisms is the upper surface of the feed platform of the lower cable mechanisms; the plane determined by the drum center of the 3 sets of lower winch mechanisms in the lower cable mechanisms is the lower surface of the base platform of the lower cable mechanisms.

[0011] Furthermore, the upper cable mechanism includes an upper base, an upper hoisting mechanism, an upper wire rope, a cable joint, a Hooke's hinge, a slewing support, and connecting bolts. The upper base is fixedly connected to the support plate by connecting bolts, and the support plate is welded to the ball joint and vertical pipe of the star-shaped frame. The cable joint is fixedly connected to the upper wire rope by alloy casting, and the cable joint is also fixedly connected to the Hooke's hinge by bolts. The Hooke's hinge is fixedly connected to the inner ring of the slewing support by connecting bolts, and the outer ring of the slewing support is fixedly connected to the connecting seat on the feed platform by connecting bolts. One end of the upper wire rope is wound around the drum of the upper hoisting mechanism, and the upper wire rope is anchored to the drum at one end. The upper wire rope has a bottom-out rope structure layout, and the length of the upper wire rope is controlled by the motor driving the drum to rotate forward and reverse. The upper cable mechanism is connected to the feed platform through the cable joint, the Hooke's hinge, and the slewing support to adapt to the change of angle of the upper wire rope during operation.

[0012] Furthermore, the cable-stayed mechanism includes a lower base, a lower winch mechanism, a lower wire rope, an open cable joint, a pin, a cross slider, an anchor seat, a rotating seat, a rotating shaft, a rotating pad, a nut, a cotter pin, and a washer. The lower base is fixedly connected to the lower inner edge of the star-shaped frame. The lower wire rope and the open cable joint are fixedly connected together by alloy casting, and the lower wire rope has an upward-outgoing rope structure. The rotating pad and the rotating seat are connected to the upper connecting plate through the rotating shaft, the washer, and the nut. The rotating pad is installed between the rotating seat and the upper connecting plate, and plays a supporting role and reduces friction when the rotating seat rotates around the rotating shaft. The anchor seat is fixedly connected to the rotating seat, and the cross slider is connected to the anchor seat through the pin. The open cable joint is connected to the lower hole of the cross slider through the pin. The washer and the cotter pin are installed at the end of the pin shaft to ensure reliable pin connection.

[0013] Furthermore, the feed platform mechanism includes a feed platform, an upper connecting plate, a connecting structure, receiver #1, receiver #2, receiver #3, receiver #4, receiver #5, and a connecting seat; the feed platform and the upper connecting plate are rigidly connected by the connecting structure; the upper connecting plate is the load-bearing body on the upper surface of the feed platform of the cable-stayed mechanism.

[0014] By adopting the above technical solution, the present invention has the following beneficial effects:

[0015] This invention uses nine sets of cable mechanisms to achieve parallel drive of the feed platform, replacing the existing secondary fine-tuning mechanism (AB swivel mechanism and Stewart rigid parallel mechanism) of the feed cabin. This solves the technical problems of small attitude angle adjustment range and small effective load of the feed cabin in the existing secondary fine-tuning mechanism, reducing the total weight of the secondary fine-tuning mechanism from 10.5 tons to 6 tons. Among them, three sets of downward cable parallel mechanisms are connected to the star frame and the connecting plate on the feed platform, increasing the anti-interference force space and torque space of the feed platform. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the FAST feed cabin provided by the present invention;

[0018] Figure 2 A schematic diagram of the cable-driven feed platform 9 of the FAST feed cabin provided by the present invention;

[0019] Figure 3 This is a top view of the feed platform of the FAST feed cabin provided by the present invention;

[0020] Figure 4 This is a cross-sectional view of the feed platform structure of the FAST feed cabin provided by the present invention;

[0021] Figure 5 A schematic diagram of the cable mechanism on the FAST feed cabin provided by this invention;

[0022] Figure 6 A schematic diagram of the FAST feed cabin cable-stayed mechanism provided by this invention;

[0023] Figure 7 This is a partial cross-sectional view of the FAST feed cabin cable-stayed mechanism provided by the present invention.

[0024] icon:

[0025] 1—Star-shaped frame; 2—Upper cable mechanism; 3—Feed platform mechanism; 4—Lower cable mechanism; 5—Feed platform; 6—Upper connecting plate; 7—Connecting structure; 8—Receiver #1; 9—Receiver #2; 10—Receiver #3; 11—Receiver #4; 12—Receiver #5; 13—Connecting seat; 14—Connecting bolt; 15—Slewing bearing; 16—Hooke hinge; 17—Cable joint; 18—Upper wire rope; 19—Upper hoisting mechanism; 20— 21—Upper base; 22—Support plate; 23—Lower base; 24—Lower wire rope; 25—Open cable joint; 26—Pin; 27—Cross slider; 28—Anchor seat; 29—Rotating seat; 30—Rotating shaft; 31—Rotating pad; 32—Washer; 33—Nut; 34—Cotter pin; 35—Washer; 36—Upper surface of base platform; 37—Lower surface of feed platform; 38—Lower surface of base platform; 39—Upper surface of feed platform. Detailed Implementation

[0026] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Combination Figure 1-7 As shown, this embodiment provides a novel FAST feed cabin based on a nine-cable-driven parallel mechanism, which includes: a star-shaped frame 1, several sets of upper cable mechanisms 2, several sets of lower cable mechanisms 4, a feed platform mechanism 3, and several feed receivers; wherein,

[0028] The fixed end of the upper cable mechanism 2 is fixedly installed on the upper part of the inner ring of the star-shaped frame 1, and the movable end of the upper cable mechanism 2 is connected to the feed platform 5 in the feed platform mechanism 3; the fixed end of the lower cable mechanism 4 is fixedly installed on the lower part of the inner ring of the star-shaped frame 1, and the movable end of the lower cable mechanism 4 is connected to the upper connecting plate 6 in the feed platform mechanism 3; the pitch angle of the feed platform 5 is adjusted by the winding and unwinding of the steel wire ropes in the upper and lower cable mechanisms; the feed receiver is installed on the feed platform mechanism.

[0029] In this embodiment, the FAST novel feed cabin includes 6 sets of upper cable mechanisms 2 and 3 sets of lower cable mechanisms 4; the hoisting mechanisms in the 6 sets of upper cable mechanisms are symmetrically distributed in pairs within the star-shaped frame 1, with 3 sets evenly distributed relative to the center line of the star-shaped frame 1, and the plane where the center of the drum of the 6 sets of hoisting mechanisms is located is the lower plane 36 of the base platform; the 6 sets of Hooke hinges 16 in the upper cable mechanism 2 are symmetrically distributed in pairs, and the plane where the center of the 6 sets of Hooke hinges 16 is located is the lower plane 37 of the feed platform; the 3 sets of lower cable mechanisms 4 are respectively installed at the symmetrical center positions of the two sets of upper cable mechanisms 2 that are symmetrically distributed in pairs, and the plane determined by the rotation center of the three sets of anchor seats 28 in the lower cable mechanism 4 is the upper plane 39 of the feed platform of the lower cable mechanism; the plane determined by the center of the drum of the three sets of lower hoisting mechanisms 23 in the lower cable mechanism 4 is the lower plane 38 of the base platform of the lower cable mechanism.

[0030] In this embodiment, the upper cable mechanism 2 includes an upper base 20, an upper hoisting mechanism 19, an upper wire rope 18, a cable joint 17, a Hooke hinge 16, a slewing support 15, and connecting bolts 14. The upper base 20 is fixedly connected to the support plate 21 by the connecting bolts 14. The support plate 21 is welded to the ball joint and vertical pipe of the star-shaped frame 1 as a whole. The cable joint 17 is fixedly connected to the upper wire rope 18 by alloy casting. The cable joint 17 is also fixedly connected to the Hooke hinge 16 by bolts. The Hooke hinge 16 is connected to the inner ring of the slewing support 15 by connecting bolts. Bolt 14 is used for fixing. The outer ring of the slewing support 15 is fixed to the connecting seat 13 on the feed platform 5 through connecting bolt 14. One end of the upper wire rope 18 is wound around the drum of the upper winch mechanism 19. The upper wire rope 18 is anchored to the drum at one end. The upper wire rope 18 has a bottom-out rope structure layout. The length of the upper wire rope 18 is controlled by the motor driving the drum to rotate forward and backward. The upper cable mechanism 2 is connected to the feed platform 5 through cable joint 17, Hooke hinge 16 and slewing support 15 to adapt to the change of angle of the upper wire rope 18 during operation.

[0031] In this embodiment, the lower cable mechanism 4 includes a lower base 22, a lower hoisting mechanism 23, a lower wire rope 24, an open cable joint 25, a pin 26, a cross slider 27, an anchor seat 28, a rotating seat 29, a rotating shaft 30, a rotating pad 31, a washer 32, a nut 33, a cotter pin 34, and a washer 35; the lower base 22 is fixedly connected to the lower inner edge of the star-shaped frame 1; the lower wire rope 24 and the open cable joint 25 are fixedly connected together by alloy casting; considering the interference factors of the internal space, the lower wire rope 24 has an upward-outgoing rope structure layout; the rotating pad... 31. The rotating seat 29 is connected to the upper connecting plate 6 via the rotating shaft 30, washer 32, and nut 33. The rotating pad 31 is installed between the rotating seat 29 and the upper connecting plate 6, which provides support and reduces friction when the rotating seat 29 rotates around the rotating shaft 30. The anchor seat 28 is fixedly connected to the rotating seat 29. The cross slider 27 is connected to the anchor seat 28 via the pin 26. The open cable joint 25 is connected to the lower hole of the cross slider 27 via the pin 26. A washer 35 and a cotter pin 34 are installed at the end of the pin 26 to ensure reliable pin connection.

[0032] In this embodiment, the feed platform mechanism 3 includes a feed platform 5, an upper connecting plate 6, a connecting structure 7, a receiver 1# 8, a receiver 2# 9, a receiver 3# 10, a receiver 4# 11, a receiver 5# 12, and a connecting seat 13. The feed platform 5 and the upper connecting plate 6 are rigidly connected by the connecting structure 7. The upper connecting plate 6 is the support body for the upper surface 39 of the feed platform of the cable-stayed mechanism 4. Five sets of receivers are installed on the feed platform mechanism 3 at the same time, and can be switched arbitrarily according to the needs of FAST observation, saving the time spent on disassembling and replacing different receivers.

[0033] In summary, this invention relates to a novel feed cabin employing a nine-cable-driven parallel mechanism for fine-tuning the feed platform's attitude. It represents an upgrade of existing feed cabins. This nine-cable-driven parallel mechanism feed cabin comprises a star-shaped frame, six sets of upper cable mechanisms, three sets of lower cable mechanisms, a feed platform, and multiple feed receivers. Compared to existing feed cabins, the A-ring and drive mechanism of the AB rotating shaft mechanism, the B-ring (Stewart upper platform) and its drive mechanism, and the Stewart six legs have been eliminated, leaving only the feed platform (Stewart feed platform). The feed platform is expanded into a frustum-shaped frame structure containing upper and lower connecting plates. The lower connecting plate mounts the feed receivers, and its outer edge also features Hooke hinges with six upper cables. The outer edge of the upper connecting plate features Hooke hinges with three lower cables. All nine cable-stayed mechanism drums are fixed to the star-shaped frame, which can be referred to as the base platform. Six drums corresponding to the upper cables are positioned slightly upwards (on the upper surface of the base platform), while three drums corresponding to the lower cables are positioned slightly downwards (on the lower surface of the base platform). This mechanism achieves the pitch angle change of the feed platform through the winding and unwinding of the six upper cables (feed angle compensation is achieved through trajectory planning, also known as angle control). The plane containing the center of the six Hooke hinges is designated as the lower surface of the feed platform; the centers of the Hooke hinges of the three lower cable mechanisms are evenly distributed in the upper connecting plate, and the plane defined by their centers is the upper surface of the feed platform. The parallel connection of the three lower cable mechanisms primarily increases the anti-interference capability of the feed platform.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A novel FAST feed cabin based on a nine-cable-driven parallel mechanism, characterized in that, include: The system comprises a star-shaped frame, several sets of upper cable-stayed mechanisms, several sets of lower cable-stayed mechanisms, a feed platform mechanism, and several feed receivers; among which, The fixed end of the upper cable mechanism is fixedly installed on the upper inner ring of the star-shaped frame, and the movable end of the upper cable mechanism is connected to the feed platform in the feed platform mechanism; the fixed end of the lower cable mechanism is fixedly installed on the lower inner ring of the star-shaped frame, and the movable end of the lower cable mechanism is connected to the upper connecting plate in the feed platform mechanism; the pitch angle of the feed platform is adjusted by the winding and unwinding of the steel wire ropes in the upper and lower cable mechanisms; the feed receiver is installed on the feed platform mechanism; The new FAST feed cabin includes 6 sets of upper cable mechanisms and 3 sets of lower cable mechanisms. The winch mechanisms within the 6 sets of upper cable mechanisms are symmetrically distributed in pairs within the star-shaped frame, with every 3 sets evenly distributed relative to the centerline of the star-shaped frame. The plane containing the center of the drums of the 6 sets of winch mechanisms is the upper surface of the base platform. The 6 sets of Hooke hinges within the upper cable mechanisms are symmetrically distributed in pairs, with the plane containing the center of the 6 sets of Hooke hinges being the lower surface of the feed platform. The 3 sets of lower cable mechanisms are respectively installed at the symmetrical center positions of the two symmetrically distributed sets of upper cable mechanisms. The plane determined by the rotation axis center of the 3 sets of anchorages in the lower cable mechanisms is the upper surface of the feed platform of the lower cable mechanisms. The plane determined by the center of the drums of the 3 sets of lower winch mechanisms in the lower cable mechanisms is the lower surface of the base platform of the lower cable mechanisms.

2. The novel FAST feed cabin based on a nine-cable-driven parallel mechanism according to claim 1, characterized in that, The upper cable mechanism includes an upper base, an upper hoisting mechanism, an upper wire rope, a cable joint, a Hooke hinge, a slewing support, and connecting bolts. The upper base is fixedly connected to the support plate by connecting bolts, and the support plate is welded to the ball joint and vertical pipe of the star-shaped frame. The cable joint is fixedly connected to the upper wire rope by alloy casting, and the cable joint is also fixedly connected to the Hooke hinge by bolts. The Hooke hinge is fixedly connected to the inner ring of the slewing support by connecting bolts, and the outer ring of the slewing support is fixedly connected to the connecting seat on the feed platform by connecting bolts. One end of the upper wire rope is wound around the drum of the upper hoisting mechanism, and the upper wire rope is anchored to the drum at one end. The upper wire rope has a bottom-out rope structure layout, and the length of the upper wire rope is controlled by the forward and reverse rotation of the drum driven by a motor. The upper cable mechanism is connected to the feed platform through the cable joint, Hooke hinge, and slewing support to adapt to the change of angle of the upper wire rope during operation.

3. The novel FAST feed cabin based on a nine-cable-driven parallel mechanism according to claim 1, characterized in that, The cable-stayed mechanism includes a lower base, a lower winch mechanism, a lower wire rope, an open cable joint, a pin, a cross slider, an anchor seat, a rotating seat, a rotating shaft, a rotating pad, a nut, a cotter pin, and a washer. The lower base is fixedly connected to the lower inner edge of the star-shaped frame. The lower wire rope and the open cable joint are fixedly connected together by alloy casting, and the lower wire rope has an upward-outgoing rope structure. The rotating pad and the rotating seat are connected to the upper connecting plate through the rotating shaft, the washer, and the nut. The rotating pad is installed between the rotating seat and the upper connecting plate, and plays a supporting role and reduces friction when the rotating seat rotates around the rotating shaft. The anchor seat is fixedly connected to the rotating seat, and the cross slider is connected to the anchor seat through the pin. The open cable joint is connected to the lower hole of the cross slider through the pin. The washer and the cotter pin are installed at the end of the pin to ensure reliable pin connection.

4. The novel FAST feed cabin based on a nine-cable-driven parallel mechanism according to claim 1, characterized in that, The feed platform mechanism includes a feed platform, an upper connecting plate, a connecting structure, receiver #1, receiver #2, receiver #3, receiver #4, receiver #5, and a connecting base; the feed platform and the upper connecting plate are rigidly connected by the connecting structure; the upper connecting plate is the load-bearing body on the upper surface of the feed platform of the cable-stayed mechanism.

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