A connecting rod type semi-active space docking mechanism buffer system and method

Abstract

A kind of connecting rod type semi-active space docking mechanism buffer system and method, including connecting rod drive buffer mechanism, docking ring, docking frame.Each group of connecting rod drive buffer mechanism is driven by motor two branch chains, while single branch chain contains spring rod and damper.When two spacecrafts are ready to dock, control motor to drive docking ring to push out to the ready docking position.In buffer stage, spring rod and damper are passively buffered to consume collision energy, motor actively generates reaction force according to preset program, drives docking mechanism, extends the buffer stroke of docking mechanism as a whole to realize buffer function;Passive spring rod, damper and active motor jointly complete the buffer of collision load and the balanced alignment of docking ring.Semi-active weak impact docking between two large spacecrafts in space is realized, impact load in docking process is reduced to some extent, direct impact on motor is reduced, with lower mechanical mechanism complexity and control complexity, good environmental adaptability.

Description

TECHNICAL FIELD

[0001] The present application relates to a space docking mechanism buffer system, in particular to a connecting rod type semi-active space docking mechanism buffer system. BACKGROUND

[0002] Space docking can combine two spacecrafts in space to form a whole that can influence each other. With the development of manned space exploration and space stations, space docking systems have also evolved and improved, and are widely used in the fields of on-orbit assembly, supply and maintenance of large cabin sections and spacecrafts. For example, the Tianzhou No. 1 cargo spaceship and the Tiangong-2 experimental cabin are connected through a space docking system to achieve the supply of goods to the space station.

[0003] The docking systems used by the Shenzhou spaceship and the space station in orbit in China are all passive mechanical and electrical buffer docking systems. Through springs and electromagnets, the docking system passively dissipates the collision energy in each direction according to the actual displacement and kinetic energy in each direction. Correspondingly, the mechanical structure of the docking system is relatively complex, with many mechanical components, which leads to high overall mass and manufacturing cost, and a long production and development cycle.

[0004] The active weak impact docking mechanism being developed at home and abroad eliminates the complex differential device between groups, and uses six independent linear motors to actively realize collision buffering during docking, which reduces the overall mass and to some extent reduces the impact force during docking. However, this system requires real-time control of the six motors, which requires high control accuracy and control complexity. SUMMARY

[0005] The technical problem solved by the present application is to overcome the shortcomings of the prior art and provide a connecting rod type semi-active space docking mechanism buffer system. By combining passive springs, dampers and active ball screws, the mechanism can realize semi-active weak impact docking between two large spacecrafts in space, to some extent reduce the impact load during docking, reduce the direct impact on the motor, and has low mechanical and control complexity and good environmental adaptability.

[0006] The technical scheme provided by the present application is as follows:

[0007] A kind of connecting rod type semi-active space docking mechanism buffer system, as active end is installed on tracking spacecraft, including docking ring, docking frame and multiple connecting rod drive buffer mechanisms;Docking frame is fixedly connected to tracking spacecraft, connecting rod drive buffer mechanism is connected between docking ring and docking frame;Each connecting rod drive buffer mechanism includes drive mechanism and RUS branch chain, drive mechanism is arranged in the inside of docking frame, the inside of docking frame is fixedly connected with shell, RUS branch chain includes driving rod, rotary rod and spring rod, rotary rod is rotatably connected to shell;Driving rod and docking ring are connected by ball twist;Rotary rod and driving rod are connected by hooke joint;One end of spring rod is connected with drive mechanism, and the other end is rotatably connected with rotary rod;Drive mechanism is used to drive the end of spring rod to move, to drive docking ring away from or close to docking frame by RUS branch chain.

[0008] Rotary rod is rotatably connected to shell by damper, and the damper is an electromagnetic rotary damper.

[0009] The drive mechanism includes a ball screw, a ball nut and a motor, the ball screw is rotatably connected with the shell, the ball screw is parallel to the axis of the docking frame, the ball nut is threadedly connected to the ball screw, the ball nut is slidably connected with the shell along the axis direction of the ball screw, the end of the spring rod is rotatably connected with the ball nut, and the motor is used to drive the ball screw to rotate bidirectionally.

[0010] The shell is fixedly connected with a limiting plate, when the docking ring is pulled back to the initial position, the rotary rod contacts with the limiting plate, and the limiting plate limits the rotary rod to continue rotating.

[0011] The spring rod is made of elastic material, and is arranged to move bidirectionally to be used for stretching or compressing.

[0012] Each drive mechanism is connected with two RUS branch chains, the two dampers are located on the opposite sides of the axis of the ball nut, the rotary rod includes a first rod and a second rod fixedly connected at one end, the first rod is rotatably connected with the damper, the spring rod is rotatably connected with the end of the first rod away from the second rod, an obtuse angle is formed between the second rod and the first rod, so that the second rod is located on the side of the first rod away from the ball nut, and the end of the second rod away from the first rod is connected with the driving rod.

[0013] The docking ring is provided with three upward guide plates, the guide plates are used to guide the passive end of the docking ring to dock with the target spacecraft;Three connecting rod drive buffer mechanisms are arranged, i.e.

[0014] The shell is fixedly connected with an upper support ear and a lower support ear, the ball screw is rotatably connected with the upper support ear and the lower support ear, and the ball nut is located between the upper support ear and the lower support ear to limit the movement stroke of the ball nut.

[0015] A buffering method of a connecting rod type semi-active space docking mechanism buffering system, comprising:

[0016] When the ball nut is in the initial position, the docking ring is in the pulled-back position close to the docking frame, the ball nut is driven to move, so that the docking ring is pushed to the ready-to-dock position away from the docking frame;

[0017] The docking ring of the tracking spacecraft contacts and is guided to align with the passive end of the target spacecraft; the capturing device arranged on the docking ring is locked with the passive end of the target spacecraft; the impact energy generated due to the inconsistent motion state of the tracking spacecraft and the target spacecraft is consumed by the connecting rod driven buffering mechanism, until the tracking spacecraft and the target spacecraft stop relative motion, the ball nut is driven to move, so that the docking ring moves to the pulled-back position close to the docking frame;

[0018] Rigidly connecting the docking ring of the tracking spacecraft and the passive end of the target spacecraft;

[0019] After the rigid connection is completed, the capturing device is unlocked, and the ball nut continues to move in the direction from the ready-to-dock position to the pulled-back position until the limit position in the direction.

[0020] Compared with the prior art, the advantages of the present application are that:

[0021] 1. Compared with the widely used passive mechanical buffering type docking mechanism, the complex mechanical components are omitted, the overall mass is reduced, the development cycle is shortened, the collision load in the docking process can be reduced to a certain extent, the in-orbit maneuverability is strong, and semi-active weak impact docking is realized.

[0022] 2. Compared with the active weak impact docking mechanism, the number of required motors is less, in the buffering process, the existence of the spring damping mechanism can reduce the instantaneous impact load on the motor. In addition, in the pulled-back position, due to the self-locking characteristic of the connecting rod driven buffering mechanism, a special docking ring locking mechanism is not required, so that the mass is reduced, the control complexity is reduced, and the requirement for the controller is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is the schematic diagram of the connecting rod type semi-active space docking mechanism buffering system (initial state) of the present application.

[0024] Figure 2 is the schematic diagram of the connecting rod type semi-active space docking mechanism buffering system when the pushing correction is performed.

[0025] Figure 3 is the perspective view of the connecting rod driven buffering mechanism when the pushing correction is performed.

[0026] Figure 4Fig. 1 is a perspective view of the invention when the connecting rod driving buffer mechanism is pulled back to the initial position.

[0027] Figure 5 Fig. 2 is a perspective view of the invention when the connecting rod driving buffer mechanism is in the initial self-locking state.

[0028] Fig. 3 is a perspective view of the invention when the connecting rod driving buffer mechanism is in the initial self-locking state. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the invention clearer, the disclosed embodiments of the invention will be described in further detail below with reference to the drawings.

[0030] Reference is made to the drawings of the invention Figures 1-5 , which further illustrate the invention. It should be understood that these examples are only used to illustrate the invention, and do not limit the protection scope of the invention.

[0031] The embodiments of the present application disclose a connecting rod type semi-active space docking mechanism buffer system, as shown in Figs. 1 and 2, which comprises a docking ring 2, a docking frame 1 and three groups of connecting rod driving buffer mechanisms as shown in Fig. 3. Figure 1 and Figure 2 . Figure 3

[0032] The docking ring 2 is installed with uniformly distributed guide plates 9. The main function of the docking ring 2 is to track the guide between the spacecraft and the target spacecraft during the docking process.

[0033] The docking ring 2 adopts three upward guide plates 9 to realize the guide alignment. The three guide plates 9 are spaced 120° on the circumference and are cross-disposed with the connecting rod driving buffer mechanism. Each guide plate 9 is provided with a capturing device 10.

[0034] The docking frame 1 of the docking mechanism buffer system is fixed on the tracking spacecraft, so that the docking mechanism buffer system is installed on the tracking spacecraft as the active end. The target spacecraft has a passive end. After the passive end is accurately docked with the docking ring 2 through the guide plates 9, it is fixed by the capturing device 10, so as to complete the capturing function between the docking ring 2 and the passive end.

[0035] The docking frame 1 mainly provides protection and support for the internal mechanism. The installation and positioning of the connecting rod driving buffer mechanism depend on the shell 8, which is fixed to the inner side of the docking frame 1.

[0036] As shown in Fig. 3 Figure 3 ​As shown, each linkage driving buffer mechanism at least includes a driving rod 3, a rotating rod 5, a spring rod 6, a motor 7, a ball screw 11, a ball nut 12 and a damper 13. The damper 13 is an electromagnetic rotary damper.

[0037] The ball screw 11 is rotationally connected with the shell 8, and the ball screw 11 is parallel to the axis of the docking frame 1. The ball nut 12 is threadedly connected to the ball screw 11, and the ball nut 12 is slidingly connected with the shell 8 along the axis direction of the ball screw 11, so that when the ball screw 11 rotates, the ball nut 12 is driven to move linearly along the axis direction of the ball screw 11.

[0038] The linkage driving buffer mechanism includes two RUS branch chains, and each RUS branch chain includes the driving rod 3, the rotating rod 5 and the spring rod 6 connected in sequence. One end of the damper 13 is fixed on the shell 8, and the other end is rotationally connected with the rotating rod 5; the branch chain end is connected with the docking ring 2, that is, the end of the driving rod 3 away from the rotating rod 5 and the docking ring 2 are connected through the ball joint 14; the rotating rod 5 is connected with the driving rod 3 through the Hooke joint 4; one end of the spring rod 6 is rotationally connected with the ball nut 12, and the other end is rotationally connected with the rotating rod 5. In the RUS branch chain, R represents a rotary pair, that is, the rotating rod 5 and the damper 13 are rotationally connected; U represents a Hooke joint, that is, the rotating rod 5 and the driving rod 3 are connected through the Hooke joint 4; S represents a ball joint, that is, the end of the driving rod 3 is connected with the ball joint 14.

[0039] Meanwhile, the rotating rod 5 rotates around the fulcrum fixed on the shell 8, and is connected through the damper 13 in the middle, so as to attenuate the collision energy conducted to the linkage driving buffer mechanism during the collision buffering.

[0040] Each linkage driving buffer mechanism is driven by a motor 7, and the motor 7 is a double-winding motor capable of bidirectional driving. The motor 7 drives the ball screw 11 to rotate, and then drives the ball nut 12 to move along the axis direction of the ball screw 11, and the ball nut 12 drives the two branch chains to act. The branch chain between the ball nut 12 and the docking ring 2 is composed of the spring rod 6, the rotating rod 5 and the driving rod 3 in sequence. In each RUS branch chain, the fulcrum of the rotating rod 5 is a rotary pair, and the degree of freedom of each branch chain itself is 6.

[0041] The linkage driving buffer mechanism is three, each linkage driving buffer mechanism includes a motor 7, and simultaneously drives two branch chains, a total of six branch chains, and when actively pushing out or pulling back, the docking ring has three degrees of freedom in space.

[0042] The motor 7 is set as a double-winding motor, which can be bidirectionally driven. When the three ball nuts move upward at the same time, the docking ring 2 is pulled back, and when the three ball nuts move downward at the same time, the docking ring 2 is pushed out.

[0043] The spring rod 6 is arranged to be bidirectional movement, and can be stretched and compressed, and has stretching and compression pre-tightening force. When not in the docking buffer working condition, no large impact load, the spring rod 6 can keep the length unchanged, at this time, it can be regarded as a common rod, which is beneficial to determine the docking ring position.

[0044] After the completion of the capture, the buffer process is carried out, in the buffer process, the impact energy is conducted to the connecting rod driving buffer mechanism by the docking ring 2, the spring rod 6 is stretched, the instantaneous impact load of the motor 7 is reduced, and the damper 13 passively consumes the collision energy. At the same time, the motor 7 actively generates a reaction force according to the preset program, drives the docking mechanism, and prolongs the buffer stroke of the whole docking mechanism to realize the buffer function; the passive spring rod 6, the damper 13 and the active motor 7 jointly complete the buffer of the collision load and the pushing out correction of the docking ring 2, and realize the semi-active control buffer function.

[0045] In the connecting rod driving buffer mechanism, the damper 13 adopts an electromagnetic rotary damper. The damper 13 main body is fixed on the docking frame 1, and provides damping for the rotation of the rotary rod 5.

[0046] As shown in Figure 4 , the limiting plate 15 is arranged on the shell 8, when the docking ring 2 is pulled back to the initial position, the limiting plate 15 limits the rotary rod 5 to continue rotating, at this time, the ball nut 12 is continuously driven upward, the spring rod 6 is compressed, until the ball nut 12 is driven to the upper limit position as shown in Figure 5 , at this time, the spring rod 6 is still in the compressed state, and the ball nut 12 is limited in the upper limit position, at this time, the connecting rod mechanism realizes self-locking, and after power-off, the connecting rod driving buffer mechanism and the docking ring can be locked.

[0047] The specific working process of the present application will be described below.

[0048] In the preparation docking stage, the motor 7 drives the ball nut 12 to move downward, so that the connecting rod driving buffer mechanism pushes the docking ring 2 out to the preparation docking position, that is, from the state of Figure 4 to the state of Figure 3 , the tracking spacecraft is moved to the preset docking capture initial condition range, and is prepared for docking.

[0049] In the guiding alignment stage, the guide plate 9 on the tracking spacecraft is in contact with the passive end of the target spacecraft, and under the action of force, the docking ring 2 is deflected to realize the guiding alignment with the target spacecraft.

[0050] In the capture stage, the docking ring 2 of the active end is in contact with the passive end of the target spacecraft, and then the capture device 10 is locked, and the capture of the target spacecraft is completed.

[0051] In the buffer stage, the impact energy is conducted to the connecting rod driving buffer mechanism by the docking ring 2, causing the spring rod 6 to stretch, reducing the instantaneous impact load on the motor 7, and the damper passively consumes the collision energy. At the same time, the motor 7 actively generates a counterforce according to the preset program to drive the docking mechanism, prolonging the buffer stroke of the docking mechanism as a whole to realize the buffer function; the passive spring rod 6 and damper 13 and the active motor 7 together complete the buffer of the collision load, realizing the semi-active control buffer function.

[0052] In the alignment pullback stage, the balance correction between the two branches of the same connecting rod driving buffer mechanism depends on the passive spring rod 6 and damper 13, and the balance between the three groups of connecting rod driving buffer mechanisms is achieved by driving the ball nut 12. When the two spacecrafts are completely aligned and stop relative motion, the motor drives the docking ring 2 to make the docking ring 2 rotate from the initial position of Figure 4 ; that is, from the state of Figure 3 to the state of Figure 4 .

[0053] In the rigid connection stage, when the docking frame surfaces of the two spacecrafts are in the close position, the docking device makes the two spacecrafts complete rigid connection and become a whole.

[0054] In the connecting rod self-locking stage, after completing the rigid connection, the capture device 10 is unlocked; when the docking ring 2 is in the initial position, the limiting plate 15 restricts the rotating rod 5 from continuing to rotate, and the ball nut 12 is continuously driven upward, and the spring rod 6 is compressed until the ball nut 12 is driven to the upper limit position as shown in Figure 5 . At this time, the spring rod 6 is still in the compressed state, and the ball nut 12 is limited in the upper limit position, and the connecting rod mechanism realizes self-locking, and after power failure, the connecting rod driving buffer mechanism and the docking ring 2 can still be locked.

[0055] The contents not described in detail in the specification of the present application are the known technology of those skilled in the art.

[0056] The present application has been described in detail in combination with specific embodiments and exemplary examples, but these descriptions cannot be understood as limitations of the present application. Those skilled in the art understand that various equivalent substitutions, modifications or improvements can be made to the technical solutions and embodiments of the present application without departing from the spirit and scope of the present application, and these all fall within the scope of the present application. The protection scope of the present application is subject to the appended claims.

Claims

1. A link-type semi-active space docking mechanism buffer system, which is installed on a tracking spacecraft as an active end, characterized in that: The docking ring (2), the docking frame (1) and a plurality of connecting rod driving buffering mechanisms are included; The docking frame (1) is fixedly connected to the tracking spacecraft, and the connecting rod driving buffering mechanism is connected between the docking ring (2) and the docking frame (1); Each connecting rod driving buffering mechanism includes a driving mechanism and a RUS branch chain, the driving mechanism is arranged inside the docking frame (1), the inside of the docking frame (1) is fixedly connected with a shell (8), the RUS branch chain includes a driving rod (3), a rotating rod (5) and a spring rod (6), the rotating rod (5) is rotationally connected to the shell (8); the driving rod (3) and the docking ring (2) are connected through a ball joint (14); the rotating rod (5) and the driving rod (3) are connected through a hooke joint (4); one end of the spring rod (6) is connected with the driving mechanism, and the other end is rotationally connected with the rotating rod (5); the driving mechanism is used for driving the end of the spring rod (6) to move, and the docking ring (2) is driven away from or close to the docking frame (1) through the RUS branch chain; The rotating rod (5) is rotationally connected to the shell (8) through a damper (13), and the damper (13) is an electromagnetic rotary damper; The driving mechanism includes a ball screw (11), a ball nut (12) and a motor (7), the ball screw (11) is rotationally connected with the shell (8), the ball screw (11) is parallel to the axis of the docking frame (1), the ball nut (12) is threadedly connected to the ball screw (11), the ball nut (12) is slidingly connected with the shell (8) along the axis direction of the ball screw (11), the end of the spring rod (6) is rotationally connected with the ball nut (12), and the motor (7) is used for driving the ball screw (11) to rotate bidirectionally; The shell (8) is fixedly connected with a limiting plate (15), when the docking ring (2) is pulled back to the initial position, the rotating rod (5) is in contact with the limiting plate (15), and the limiting plate (15) limits the rotating rod (5) to continue to rotate; Each driving mechanism is connected with two RUS branch chains, two dampers (13) are located on the opposite sides of the axis of the ball nut (12), the rotating rod (5) includes a first rod and a second rod fixedly connected at one end, the first rod is rotationally connected with the damper (13), the spring rod (6) is rotationally connected with the end of the first rod away from the second rod, and an obtuse angle is formed between the first rod and the second rod, so that the second rod is located on the side of the first rod away from the ball nut (12), and the end of the second rod away from the first rod is connected with the driving rod (3).

2. A link-type semi-active spatial docking mechanism cushioning system according to claim 1, characterized in that: The spring rod (6) is made of a material with elasticity; the spring rod (6) is arranged to move bidirectionally and is used for stretching or compressing.

3. A connecting rod type semi-active spatial docking mechanism damping system according to claim 1, characterized in that: The docking ring (2) is provided with three upward guide plates (9), the guide plates (9) are used for guiding the docking ring (2) to dock with the passive end of the target spacecraft; three connecting rod driving buffering mechanisms are arranged, namely three driving mechanisms, and the driving mechanisms and the guide plates (9) are arranged in a staggered manner in the circumferential direction of the docking frame (1).

4. A connecting rod type semi-active spatial docking mechanism damping system according to claim 1, characterized in that: The shell (8) is fixedly connected with an upper supporting lug and a lower supporting lug, the ball screw (11) is rotationally connected with the upper supporting lug and the lower supporting lug, and the ball nut (12) is located between the upper supporting lug and the lower supporting lug to limit the movement stroke of the ball nut (12).

5. The method of claim 1-4, wherein, The docking ring (2), the docking frame (1) and a plurality of connecting rod driving buffering mechanisms are included; When the ball nut (12) is in the initial position, the docking ring (2) is in the pulled-back position close to the docking frame (1), the ball nut (12) is driven to move, so that the docking ring (2) is pushed to the ready-to-dock position away from the docking frame (1); The docking ring (2) of the tracking spacecraft contacts and aligns with the passive end of the target spacecraft; the capture device (10) provided on the docking ring (2) is locked with the passive end of the target spacecraft; the impact energy generated by the inconsistent motion state of the tracking spacecraft and the target spacecraft is consumed by the connecting rod driven buffer mechanism until the tracking spacecraft and the target spacecraft stop relative motion; the ball nut (12) is driven to move, so that the docking ring (2) moves to the pulled-back position close to the docking frame (1); Rigidly connecting the docking ring (2) of the tracking spacecraft and the passive end of the target spacecraft; After the rigid connection is completed, the capture device (10) is unlocked, and the ball nut (12) continues to move in the direction from the ready-to-dock position to the pulled-back position until it reaches the limit position in the direction.

6. The buffering method of claim 5, wherein, The impact energy generated by the inconsistent motion state of the tracking spacecraft and the target spacecraft is consumed by the connecting rod driven buffer mechanism until the tracking spacecraft and the target spacecraft stop relative motion, including: driving the ball nut (12) of the connecting rod driven buffer mechanism to move to extend the buffer stroke until the tracking spacecraft and the target spacecraft stop relative motion.

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