Connecting rod type semi-active space docking mechanism buffering system and method

Abstract

The invention discloses a connecting rod type semi-active space docking mechanism buffering system and method. The connecting rod type semi-active space docking mechanism buffering system comprises a connecting rod driving buffering mechanism, a docking ring and a docking frame. Each set of connecting rod driving buffering mechanism drives two branch chains through a motor, and meanwhile each branch chain comprises a spring rod and a damper. And when the two spacecrafts are ready for butt joint, the motor is controlled to drive the butt joint ring to be pushed out to the butt joint preparation position. In the buffering stage, the spring rod piece and the damper are passively buffered to consume collision energy, the motor actively generates counter-acting force according to a preset program to drive the butt joint mechanism, and the overall buffering stroke of the butt joint mechanism is prolonged to achieve the buffering function; the passive spring rod piece, the damper and the active motor jointly complete buffering of collision loads and balance alignment of the butt joint rings. The semi-active weak impact docking between two large spacecrafts in the space is realized, the impact load in the docking process is reduced to a certain extent, the direct impact on a motor is reduced, the mechanical mechanism complexity and the control complexity are low, and the environmental adaptability is good.

Description

Technical Field

[0001] The invention relates to a space docking mechanism buffer system, in particular to a connecting rod type semi-active space docking mechanism buffer system. Background Art

[0002] Space docking allows two spacecraft to complete the system integration in space, turning two independent individuals into a whole that can influence each other. With the development of manned space exploration and space stations, the space docking system has also been continuously evolving and improving. It is widely used in the fields of space stations, large modules such as spacecraft, and on-orbit assembly, replenishment, and maintenance of aircraft. For example, the Tianzhou-1 cargo spacecraft and the Tiangong-2 experimental module completed docking through the space docking system to realize the replenishment of space station cargo.

[0003] The docking systems used by my country's Shenzhou spacecraft and space stations on orbit all adopt electromechanical passive buffer docking systems. Through springs and electromagnetics, the docking system passively consumes the collision energy in each direction according to the actual displacement and kinetic energy in each direction. Accordingly, the mechanical structure of the docking system is relatively complex, with many mechanical components, which leads to high overall quality and manufacturing costs, and a long production and development cycle.

[0004] The active weak-impact docking mechanism being developed at home and abroad eliminates the complex inter-group differential device and uses six independent linear motors to actively achieve collision buffering during the docking process, which reduces the overall mass and reduces the collision force during the docking process to a certain extent. However, the system requires real-time control of the six motors, and the control accuracy and control complexity are relatively high. Summary of the invention

[0005] The technical problem solved by the present application is: to overcome the deficiencies of the prior art and provide a connecting rod type semi-active space docking mechanism buffer system. During buffering, by combining passive springs, damping and active ball screws, the mechanism can realize semi-active weak impact docking between two large spacecraft in space, reduce the impact load during the docking process to a certain extent, reduce the direct impact on the motor, have lower mechanical structure complexity and control complexity, and have good environmental adaptability.

[0006] The technical solutions provided by this application are as follows:

[0007] A connecting rod type semi-active space docking mechanism buffer system is installed on a tracking spacecraft as an active end, comprising a docking ring, a docking frame and a plurality of connecting rod driven buffer mechanisms; the docking frame is fixedly connected to the tracking spacecraft, and the connecting rod driven buffer mechanism is connected between the docking ring and the docking frame; each connecting rod driven buffer mechanism comprises a driving mechanism and a RUS branch chain, the driving mechanism is arranged on the inner side of the docking frame, a shell is fixedly connected to the inner side of the docking frame, the RUS branch chain comprises a driving rod, a rotating rod and a spring rod, and the rotating rod is rotatably connected to the shell; the driving rod and the docking ring are connected by a ball joint; the rotating rod and the driving rod are connected by a Hooke's hinge; one end of the spring rod is connected to the driving mechanism, and the other end is rotatably connected to the rotating rod; the driving mechanism is used to drive the end of the spring rod to move, so as to drive the docking ring away from or close to the docking frame through the RUS branch chain.

[0008] The rotating rod is rotationally connected to the housing through a damper, and the damper is an electromagnetic rotating damper.

[0009] The driving mechanism includes a ball screw, a ball nut and a motor. The ball screw is rotatably connected to 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 and the shell are slidingly connected along the axis of the ball screw. The end of the spring rod is rotatably connected to the ball nut. The motor is used to drive the ball screw to rotate in both directions.

[0010] The shell is fixedly connected to the limiting plate. When the docking ring is pulled back to the initial position, the rotating rod contacts the limiting plate, and the limiting plate limits the rotating rod from continuing to rotate.

[0011] The spring rod is made of elastic material; the spring rod is configured to move in both directions and is used for stretching or compression.

[0012] Each of the driving mechanisms is connected to two RUS branches, and the two dampers are located on opposite sides outside the axis of the ball nut. The rotating rod includes a first rod and a second rod fixedly connected at one end, the first rod is rotatably connected to the damper, the spring rod is rotatably connected to the end of the first rod away from the second rod, and 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 to the driving rod.

[0013] The docking ring is provided with three upward guide plates, which are used to guide the docking ring to dock with the passive end of the target spacecraft; three connecting rod drive buffer mechanisms are provided, that is, there are three drive mechanisms, and the drive mechanisms and the guide plates are staggered in the circumferential direction of the docking frame.

[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 moving stroke of the ball nut.

[0015] A buffering method for 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 a retracted position close to the docking frame, driving the ball nut to move so that the docking ring is pushed out in a direction away from the docking frame to a ready-to-dock position;

[0017] The docking ring of the tracking spacecraft contacts and guides the passive end of the target spacecraft to align; the capture device provided on the docking ring is locked with the passive end of the target spacecraft; the impact energy generated by the inconsistency of the motion states of the tracking spacecraft and the target spacecraft is consumed by the connecting rod driving buffer 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 toward the direction close to the docking frame to the retracted position;

[0018] A rigid connection is made between the docking ring of the tracking spacecraft and the passive end of the target spacecraft;

[0019] After the rigid connection is completed, the capture device is unlocked, and the ball nut continues to move along the moving direction from the ready-to-dock position to the retracted position until it is located at the limit position in this direction.

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

[0021] 1. Compared with the widely used passive mechanical buffer docking mechanism, it abandons the complex mechanical components, reduces the overall quality and shortens the development cycle. At the same time, it can also reduce the collision load during the docking process to a certain extent, has strong on-orbit controllability, and realizes semi-active weak impact docking.

[0022] 2. Compared with the active weak impact docking mechanism, fewer motors are required. During the buffering process, the presence of the spring damping mechanism can reduce the instantaneous impact load on the motor. In addition, in the retracted position, since the connecting rod drive buffer mechanism has a self-locking characteristic, a special docking ring locking mechanism is not required. Therefore, while reducing the mass, the complexity of control is reduced, and the requirements for the controller are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0024] Figure 2 It is a schematic diagram of the push-out correction of the buffer system of the connecting rod type semi-active space docking mechanism of the present invention.

[0025] Figure 3 It is a perspective view of the connecting rod driving the buffer mechanism of the present invention when it is pushed out for correction.

[0026] Figure 4It is a perspective view of the connecting rod driving buffer mechanism of the present invention when it is just pulled back to the initial state.

[0027] Figure 5 This is a structural perspective view of the connecting rod driving buffer mechanism of the present invention when it is in the initial self-locking state

[0028] Markings in the figure: 1-docking frame; 2-docking ring; 3-driving rod; 4-Hook's hinge; 5-rotating rod; 6-spring rod; 7-motor; 8-housing; 9-guide plate; 10-capture device; 11-ball screw; 12-ball nut; 13-damper; 14-ball hinge; 15-limiting plate. DETAILED DESCRIPTION

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

[0030] See the attached Figure 1-5 It should be understood that these embodiments are only used to illustrate the present invention, but not to limit the protection scope of the present invention.

[0031] The present application embodiment discloses a connecting rod type semi-active space docking mechanism buffer system, such as Figure 1 and Figure 2 As shown, it includes a docking ring 2, a docking frame 1 and three groups such as Figure 3 The connecting rod shown drives the buffer mechanism.

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

[0033] The docking ring 2 uses three upward guide plates 9 to achieve guiding alignment. The three guide plates 9 are spaced 120° apart on the circumference and are arranged crosswise 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 an active end. The target spacecraft has a passive end, which can be accurately docked with the docking ring 2 through the guide plate 9 and then fixed by the capture device 10, thereby completing the capture 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, and the shell 8 is fixedly connected to the inner side of the docking frame 1.

[0036] like Figure 3As shown, each connecting rod driving buffer mechanism at least comprises 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 rotatably connected to the housing 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 slidably connected to the housing 8 along the axis 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 of the ball screw 11.

[0038] The connecting rod drive buffer mechanism includes two RUS branches, each of which includes a driving rod 3, a rotating rod 5 and a spring rod 6 connected in sequence. One end of the damper 13 is fixed on the housing 8, and the other end is rotatably connected to the rotating rod 5; the end of the branch chain is connected to 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 a ball joint 14; the rotating rod 5 is connected to the driving rod 3 through a Hooke's hinge 4; one end of the spring rod 6 is rotatably connected to the ball nut 12, and the other end is rotatably connected to the rotating rod 5. In the RUS branch chain, R represents a rotating pair, that is, a rotatable connection between the rotating rod 5 and the damper 13; U represents a Hooke's hinge, that is, the rotating rod 5 is connected to the driving rod 3 through a Hooke's hinge 4; S represents a ball joint, that is, a ball joint 14 connected to the end of the driving rod 3.

[0039] At the same time, the rotating rod 5 rotates around the fulcrum fixed to the housing 8, and the middle is connected through the damper 13. During collision buffering, the collision energy transmitted to the connecting rod driving buffer mechanism is attenuated.

[0040] Each connecting rod driving buffer mechanism is driven by a motor 7, which 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 of the ball screw 11, and the ball nut 12 drives the two branch chains to move. The branch chain from the ball nut 12 to the docking ring 2 is composed of a spring rod 6, a rotating rod 5, and a driving rod 3. In each RUS branch chain, the fulcrum of the rotating rod 5 is a revolute pair, and each branch chain has 6 degrees of freedom.

[0041] There are three connecting rod driven buffer mechanisms, each of which includes a motor 7, which drives two branch chains at the same time, with a total of six branch chains. When actively pushed out or pulled back, the docking ring has three degrees of freedom in space.

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

[0043] The spring rod 6 is set to move in both directions, can be stretched and compressed, and has both tensile and compressive preloads. When not in the docking buffering condition, there is no large impact load, and the spring rod 6 can keep the same length. At this time, it can be regarded as an ordinary rod, which is conducive to determining the docking ring posture.

[0044] After the capture is completed, the buffering process is carried out. During the buffering process, the impact energy is transmitted from the docking ring 2 to the connecting rod driving the buffering mechanism, causing the spring rod 6 to stretch, reducing the instantaneous impact load on the motor 7, 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 extends the overall buffering stroke of the docking mechanism to achieve the buffering function; the passive spring rod 6, the damper 13 and the active motor 7 jointly complete the buffering of the collision load and the push-out correction of the docking ring 2, realizing the semi-active control buffering function.

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

[0046] like Figure 4 As shown, a limit plate 15 is arranged on the housing 8. When the docking ring 2 is pulled back to the initial position, the limit plate 15 limits the rotation of the rotating rod 5. At this time, the ball nut 12 is driven upward, and the spring rod 6 is compressed until the ball nut 12 is driven to the position as shown in FIG. Figure 5 As shown in the upper limit position, the spring rod 6 is still in a compressed state, limiting the ball nut 12 to the upper limit position. At this time, the connecting rod mechanism realizes self-locking. After power failure, the connecting rod drive buffer mechanism and the docking ring can be locked.

[0047] The specific working process of the present invention is described below.

[0048] In the preparation stage for docking, the motor 7 drives the ball nut 12 to move downward, so that the connecting rod drives the buffer mechanism to push the docking ring 2 to the preparation position for docking, that is, Figure 4 Status to Figure 3 state, tracking the spacecraft movement to the preset range of initial docking capture conditions, and preparing for docking.

[0049] During the guidance and alignment stage, the guide plate 9 on the tracking spacecraft contacts the passive end of the target spacecraft, and under the action of the force, the docking ring 2 deflects to achieve guidance and alignment with the target spacecraft.

[0050] During the capture phase, the docking ring 2 at the active end fits with the passive end of the target spacecraft, and then the capture device 10 is locked to complete the capture of the target spacecraft.

[0051] In the buffering stage, the impact energy is transmitted from the docking ring 2 to the connecting rod driving buffer mechanism, 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 reaction force according to the preset program, drives the docking mechanism, and extends the overall buffering stroke of the docking mechanism to achieve the buffering function; the passive spring rod 6, damper 13 and active motor 7 jointly complete the buffering of the collision load, realizing the semi-active control buffering function.

[0052] During the alignment and retraction phase, the balance correction between the two chains of the same link-driven buffer mechanism depends on the passive spring rod 6 and the damper 13. The balance between the three sets of link-driven buffer mechanisms is achieved by driving the ball nut 12. When the two spacecraft are fully aligned and stop relative motion, the motor drives the docking ring 2 to retract so that the docking ring 2 is in Figure 4 The initial position of Figure 3 Status to Figure 4 status.

[0053] During the rigid connection stage, when the docking frames of the two spacecraft are in close position, the docking device completes the rigid connection of the two spacecraft and becomes a whole.

[0054] In the self-locking stage of the connecting rod, after the rigid connection is completed, the capture device 10 is unlocked; when the docking ring 2 is in the initial position, the limit plate 15 limits the rotation of the rotating rod 5 to continue 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 position as shown in FIG. Figure 5 At this time, the spring rod 6 is still in a compressed state, limiting the ball nut 12 to the upper limit position, and the connecting rod mechanism realizes self-locking. 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 this application specification belong to the common knowledge of those skilled in the art.

[0056] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A connecting rod type semi-active space docking mechanism buffer system, characterized in that: It comprises a docking ring (2), a docking frame (1) and a plurality of connecting rod driving buffer mechanisms; The docking frame (1) is fixedly connected to the tracking spacecraft, and the connecting rod driving buffer mechanism is connected between the docking ring (2) and the docking frame (1); Each connecting rod driving buffer mechanism comprises a driving mechanism and a RUS branch chain. A shell (8) is fixedly connected to the inner side of the docking frame (1). The driving mechanism is installed on the shell (8). The RUS branch chain comprises a driving rod (3), a rotating rod (5) and a spring rod (6) which are connected in sequence. The rotating rod (5) is rotatably connected to the shell (8). The driving rod (3) and the docking ring (2) are connected via a ball joint (14). The rotating rod (5) and the driving rod (3) are connected via a Hooke's hinge (4). One end of the spring rod (6) is connected to the driving mechanism, and the other end is rotatably connected to the rotating rod (5). The driving mechanism is used to drive the end of the spring rod (6) to move, thereby driving the docking ring (2) to move away from or close to the docking frame (1) via the RUS branch chain.

2. The connecting rod type semi-active space docking mechanism buffer system according to claim 1, characterized in that: The rotating rod (5) is rotationally connected to the housing (8) via a damper (13), and the damper (13) is an electromagnetic rotating damper.

3. The connecting rod type semi-active space docking mechanism buffer system according to claim 1, characterized in that: The driving mechanism comprises a ball screw (11), a ball nut (12) and a motor (7); the ball screw (11) is rotatably connected to a housing (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) and the housing (8) are slidably connected along the axis of the ball screw (11); the end of the spring rod (6) is rotatably connected to the ball nut (12); and the motor (7) is used to drive the ball screw (11) to rotate in both directions.

4. The connecting rod type semi-active space docking mechanism buffer system according to claim 1, characterized in that: The housing (8) is fixedly connected to a limiting plate (15); when the docking ring (2) is pulled back to the initial position, the rotating rod (5) contacts the limiting plate (15), and the limiting plate (15) limits the rotating rod (5) from continuing to rotate.

5. The connecting rod type semi-active space docking mechanism buffer system according to claim 1, characterized in that: The spring rod (6) is made of an elastic material; the spring rod (6) is configured to move in both directions and is used for stretching or compression.

6. The connecting rod type semi-active space docking mechanism buffer system according to claim 1, characterized in that: Each of the driving mechanisms is connected to two RUS branches, and two dampers (13) are located on opposite sides outside the axis of the ball nut (12). The rotating rod (5) comprises a first rod and a second rod fixedly connected at one end, the first rod is rotatably connected to the damper (13), the spring rod (6) is rotatably connected to the end of the first rod away from the second rod, and 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 (12), and the end of the second rod away from the first rod is connected to the driving rod (3).

7. The connecting rod type semi-active space docking mechanism buffer system according to claim 6, characterized in that: The docking ring (2) is provided with three upward guide plates (9), and the guide plates (9) are used to guide the docking ring (2) to dock with the passive end of the target spacecraft; three connecting rod drive buffer mechanisms are provided, that is, there are three drive mechanisms, and the drive mechanisms and the guide plates (9) are staggered in the circumferential direction of the docking frame (1).

8. The connecting rod type semi-active space docking mechanism buffer system according to claim 2, characterized in that: The housing (8) is fixedly connected with an upper support ear and a lower support ear, the ball screw (11) is rotatably connected to both the upper support ear and the lower support ear, and the ball nut (12) is located between the upper support ear and the lower support ear to limit the movement stroke of the ball nut (12).

9. A buffering method for a buffering system of a link-type semi-active spatial docking mechanism according to any one of claims 1 to 8, characterized in that: include: When the ball nut (12) is located at the initial position, the docking ring (2) is located at a retracted position close to the docking frame (1), and the ball nut (12) is driven to move, so that the docking ring (2) is pushed out in a direction away from the docking frame (1) to a ready-to-dock position; The docking ring (2) of the tracking spacecraft contacts and guides the passive end of the target spacecraft to align; 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 inconsistency of the motion states of the tracking spacecraft and the target spacecraft is consumed by the connecting rod driving 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 in a direction close to the docking frame (1) to a retracted position; Rigidly connecting the docking ring (2) of the tracking spacecraft to 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 along the moving direction from the ready-to-dock position to the retracted position until it is located at the limit position in this direction.

10. The buffering method according to claim 9, characterized in that: The impact energy generated by the inconsistency of the motion states of the tracking spacecraft and the target spacecraft is consumed by the connecting rod driving the buffer mechanism until the tracking spacecraft and the target spacecraft stop relative motion, including: driving the ball nut (12) of the connecting rod driving the buffer mechanism to move to extend the buffer stroke until the tracking spacecraft and the target spacecraft stop relative motion.

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