Lockable three-dimensional rotational metamorphic parallel mechanism based on coupling chain

Abstract

The present invention discloses a lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain, wherein a plurality of platforms are arranged in sequence and spaced apart; a kinematic chain is connected in parallel between two adjacent platforms, constraining the three-dimensional rotation of one of the two adjacent platforms relative to the other; each kinematic chain parallel unit includes a plurality of kinematic chains, each of which includes a first branch and a second branch, the plurality of first branches are connected in parallel to two adjacent platforms, and the plurality of second branches are connected in sequence between two adjacent first branches; in the same kinematic chain parallel unit, when each kinematic chain has a singular position, the second branch can use its own local degree of freedom to lock and unlock the first branch. The present invention can solve the high load-bearing problem of the locking mechanism, while avoiding the displacement fluctuation of the energy-type multistable structure under impact load and the unidirectional load-bearing problem of the contact metamorphic.

Description

Technical Field

[0001] The present invention relates to the technical field of three-dimensional rotation mechanisms, and in particular to a lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain. Background Art

[0002] Deployable structures are widely used in industries such as industry, medicine, and exploration. Their advantages lie in their easily deployable collapsed state, adaptable deployed state to different requirements, and controllable deployment path. After the deployed structure has completed its deformation, it needs to be locked to resist the load and maintain its shape. Traditional locking designs usually involve designing additional locking mechanisms on the existing deployment structure. For example, the movable joints of the mechanism are locked by means of latches, mast member tracks, barbed grooves, spring devices, etc., which reduces the degree of freedom and achieves locking of the overall structure.

[0003] Among multistable structural designs that combine deployment and locking, energy-based and contact-metamorphosis multistable structures are predominant. Energy-based multistable structures rely on the minimum potential energy at a specific posture to achieve locking. Existing energy storage structures include curved beams, springs, electromagnets, and origami structures. Contact-metamorphosis relies on changing the contact surface or interaction force, thereby altering the overall topology to achieve locking. The few designs that exploit structural singularities are concentrated in Bricard-like single rings and universal joints, and are generally not suitable for locking.

[0004] Traditional locking mechanisms are additional components to the deployed structure. Because they limit and lock the movable joint, they increase the overall floating mass, thereby increasing the required drive power. Furthermore, the track within the locking mechanism restricts the mechanism's degrees of freedom, reducing deployment flexibility. Furthermore, the mechanism that locks the joint from movable to locked also becomes the primary load-bearing structure, placing high demands on the locking mechanism's strength.

[0005] While energy-based multistable structures can support their own loads, their output platforms experience displacement fluctuations when exposed to sudden or cyclical loads, making them unsuitable for applications requiring sustained deformation. Contact metamorphic cells, while free of displacement fluctuations, can only withstand unidirectional loads. Summary of the Invention

[0006] The present invention aims to address at least one of the technical problems existing in the prior art. To this end, one objective of the present invention is to propose a lockable three-dimensional rotational metamorphic parallel mechanism based on a coupling chain. This mechanism is capable of three-dimensional rotational deformation and locking, resolving the high load-bearing capacity of the locking mechanism while avoiding the displacement fluctuations of energy-based multistable structures under impact loads and the unidirectional load-bearing capacity of contact metamorphic cells.

[0007] The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to an embodiment of the present invention includes:

[0008] Platform, there are multiple platforms, and the multiple platforms are arranged in sequence at intervals;

[0009] A motion chain parallel unit, wherein the motion chain parallel units are connected one-to-one between two adjacent platforms, and each motion chain parallel unit is used to constrain the three-dimensional rotation of one of the corresponding two adjacent platforms relative to the other platform; each motion chain parallel unit includes multiple motion chains, and the multiple motion chains respectively include a first branch chain and a second branch chain, and the multiple first branches are connected in parallel to the two adjacent platforms at intervals along the circumferential direction, and the multiple second branches are connected one-to-one between the two adjacent first branches in sequence; in the same motion chain parallel unit, when each motion chain has a singular position during the three-dimensional rotation of one of the corresponding two adjacent platforms relative to the other platform, the second branch chain can use its own local degree of freedom to lock and unlock the first branch chain.

[0010] According to the locking three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the embodiment of the present invention, a motion chain parallel unit is set between each two adjacent platforms, and the multiple motion chains in each motion chain parallel unit respectively include a first branch chain and a second branch chain. The multiple first branches are connected in parallel between the corresponding two adjacent platforms at intervals along the circumferential direction, and the multiple second branches are connected one by one between the two adjacent first branches. The motion chain parallel unit of this structure can realize the three-dimensional rotation of one platform relative to the other platform in the corresponding two adjacent platforms. In the same kinematic chain parallel unit, when a singular position occurs in each kinematic chain during the three-dimensional rotation of one of the corresponding two adjacent platforms relative to the other platform, the second branch can lock the first branch through its own local degree of freedom, thereby preventing relative movement between the corresponding two adjacent platforms. In this way, the locking of a specific state of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the embodiment of the present invention can be achieved, and after locking, the first branch and the second branch in the kinematic chain share the load. Therefore, the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the embodiment of the present invention has higher load-bearing performance after locking, while avoiding the displacement fluctuation of the energy-type multi-stable structure under impact load and the unidirectional load-bearing problem of the contact metamorphic. The first branch in the locked state can also be unlocked through the local degree of freedom of the second branch, so that one of the corresponding two adjacent platforms can rotate three-dimensionally relative to the other platform.

[0011] The locking three-dimensional rotating metamorphic parallel mechanism based on the coupling chain of the embodiment of the present invention integrates the deployment and locking into one mechanism, and adopts the motion chain form of the coupled metamorphic cell to switch the deformation state and the locking state. In the locked state, the motion chain itself is used to carry the load to solve the high load-bearing problem of the locking mechanism, while avoiding the displacement fluctuation of the energy-type multi-stable structure under impact load and the unidirectional load-bearing problem of the contact metamorphic cell.

[0012] In some embodiments, in the same kinematic chain parallel unit, for the same kinematic chain, the first branch includes a first rod member, a second rod member and a third rod member, one end of the first rod member is pivotally hinged to one of the corresponding two adjacent platforms, the other end of the first rod member is pivotally connected to one end of the second rod member, the other end of the second rod member is pivotally connected to one end of the third rod member, the other end of the third rod member is pivotally connected to the other of the corresponding two adjacent platforms, one end of the second branch is pivotally connected to the middle of the first rod member, and the other end of the second branch is pivotally connected to the middle of the third rod member of the other kinematic chain.

[0013] In some embodiments, the second branch chain includes a fourth rod member, a fifth rod member, and a sixth rod member, one end of the fourth rod member is pivotally connected to the middle portion of the first rod member, the other end of the fourth rod member is pivotally connected to one end of the fifth rod member, the other end of the fifth rod member is pivotally connected to one end of the sixth rod member, and the other end of the sixth rod member is pivotally connected to the middle portion of the third rod member of the other kinematic chain;

[0014] When the motion chain appears in a singular position, the pivot axis of one end of the second rod member is coaxial with the pivot axis of one end of the fifth rod member, the pivot axis of the other end of the second rod member is coaxial with the pivot axis of the other end of the fifth rod member, and the pivot axis of one end of the fourth rod member is coaxial with the pivot axis of the other end of the sixth rod member. At this time, the second branch chain can rotate around the coaxial pivot axis of one end of the fourth rod member and the other end of the sixth rod member. If the pivot axis of one end of the second rod member is not coaxial with the pivot axis of one end of the fifth rod member and the pivot axis of one end of the fourth rod member is not coaxial with the pivot axis of the other end of the sixth rod member, the second branch chain locks the first branch chain.

[0015] In some embodiments, the rotation pairs at both ends and the middle of the first rod member are not in the same plane with each other, the rotation pairs at both ends of the second rod member are not in the same plane with each other, the rotation pairs at both ends and the middle of the third rod member are not in the same plane with each other, the rotation pairs at both ends of the fourth rod member are not in the same plane with each other, the rotation pairs at both ends of the fifth rod member are not in the same plane with each other, and the rotation pairs at both ends of the sixth rod member are not in the same plane with each other.

[0016] In some embodiments, with respect to the same motion chain parallel unit, the corresponding two adjacent platforms are respectively provided with multiple mounting parts, the multiple mounting parts on one of the corresponding two adjacent platforms are directly opposite to the multiple mounting parts on the other platform, and the two ends of the multiple first branches are respectively connected to the multiple mounting parts on the corresponding two adjacent platforms.

[0017] In some embodiments, both ends of each first branch chain are respectively connected to two adjacent diagonally opposite mounting portions on two corresponding adjacent platforms.

[0018] In some embodiments, in the same kinematic chain, the second branch is located outside the first branch; when the kinematic chain is in a singular position, the second branch rotates outward or inward relative to the first branch to lock the first branch.

[0019] In some embodiments, the number of kinematic chains in the kinematic chain parallel units between two different adjacent platforms may be the same or different.

[0020] In some embodiments, the platform is a ring.

[0021] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0023] Figure 1 This is a front view of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention;

[0024] Figure 2 This is a front view of the first branch of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention;

[0025] Figure 3 This is a left view of the first branch of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention;

[0026] Figure 4 This is a front view of the second branch of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention;

[0027] Figure 5 This is a left view of the second branch of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention;

[0028] Figure 6 Schematic diagram of the deformation state of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention;

[0029] Figure 7 Schematic diagram of the locked state of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention;

[0030] Figure 8 Schematic diagram of the positional relationship between the second branch and the first branch of the kinematic chain in the locked state of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention;

[0031] Figure 9 Schematic diagram of the second branched chain morphology in the locked state of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention.

[0032] Reference numerals:

[0033] Platform 1; mounting portion 11; kinematic chain parallel unit 2; kinematic chain 21; first branch chain 211; first rod member 2111; second rod member 2112; third rod member 2113; second branch chain 212; fourth rod member 2121; fifth rod member 2122; and sixth rod member 2123. DETAILED DESCRIPTION

[0034] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0035] The following combination Figures 1 to 9 To describe the lockable three-dimensional rotational metamorphic parallel mechanism based on the coupling chain according to an embodiment of the present invention.

[0036] like Figures 1 to 9 As shown, the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain according to an embodiment of the present invention includes a platform 1 and a kinematic chain parallel unit 2.

[0037] Specifically, there are multiple platforms 1, and the multiple platforms 1 are arranged in sequence. For example, the number of platforms 1 can be two, three or more, for example, Figure 1It is shown that three platforms 1 are arranged at intervals in the vertical direction.

[0038] The kinematic chain parallel units 2 are connected one-to-one between two adjacent platforms 1. That is, one kinematic chain parallel unit 2 is provided between each two adjacent platforms 1. Each kinematic chain parallel unit 2 is used to constrain the three-dimensional rotation of one of the two adjacent platforms 1 relative to the other platform 1. That is, the kinematic chain parallel unit 2 is provided to control the three-dimensional rotation range of one of the two adjacent platforms 1 relative to the other platform 1.

[0039] Each kinematic chain parallel unit 2 includes multiple kinematic chains 21, each of which includes a first branch chain 211 and a second branch chain 212. The multiple first branch chains 211 are connected in parallel to two adjacent platforms 1 at intervals along the circumferential direction, and the multiple second branch chains 212 are connected one-to-one between two adjacent first branch chains 211. In the same kinematic chain parallel unit 2, when each kinematic chain 21 appears in a singular position during the three-dimensional rotation of one platform 1 of the corresponding two adjacent platforms 1 relative to the other platform 1, the second branch chain 212 can use its own local degree of freedom to lock and unlock the first branch chain 211. Specifically, when the kinematic chain 21 reaches a singular position during the three-dimensional rotation of one of the two adjacent platforms 1 relative to the other platform 1, the second branch 212 can lock the first branch 211 through its own local degree of freedom, thereby preventing relative motion between the two adjacent platforms 1. Thus, the locking of a specific state of the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism of the embodiment of the present invention can be achieved. After locking, the first branch 211 and the second branch 212 in the kinematic chain 21 share the load. Therefore, the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism of the embodiment of the present invention has higher load-bearing performance after locking, while avoiding the displacement fluctuation of the energy-type multistable structure under impact load and the unidirectional load-bearing problem of the contact metamorphic. The first branch 211 in the locked state can also be unlocked through the local degree of freedom of the second branch 212, allowing one of the two adjacent platforms 1 to perform three-dimensional rotation relative to the other platform 1.

[0040] According to the locking three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of an embodiment of the present invention, a motion chain parallel unit 2 is set between each two adjacent platforms 1, and the multiple motion chains 21 in each motion chain parallel unit 2 respectively include a first branch chain 211 and a second branch chain 212. The multiple first branches 211 are connected in parallel between the corresponding two adjacent platforms 1 at intervals along the circumferential direction, and the multiple second branches 212 are connected one by one between the two adjacent first branches 211. The motion chain parallel unit 2 of this structure can realize the three-dimensional rotation of one platform 1 relative to the other platform 1 in the corresponding two adjacent platforms 1. In the same kinematic chain parallel unit 2, when each kinematic chain 21 reaches a singular position during the three-dimensional rotation of one of the corresponding two adjacent platforms 1 relative to the other platform 1, the second branch 212 can lock the first branch 211 through its own local degree of freedom, thereby preventing relative motion between the corresponding two adjacent platforms 1. Thus, the locking of a specific state of the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism of the embodiment of the present invention can be achieved. After locking, the first branch 211 and the second branch 212 in the kinematic chain 21 share the load. Therefore, the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism of the embodiment of the present invention has higher load-bearing performance after locking, while avoiding the displacement fluctuation of the energy-type multistable structure under impact load and the unidirectional load-bearing problem of the contact metamorphic. The first branch 211 in the locked state can also be unlocked through the local degree of freedom of the second branch 212, allowing one of the corresponding two adjacent platforms 1 to rotate three-dimensionally relative to the other platform 1.

[0041] The locking three-dimensional rotating metamorphic parallel mechanism based on the coupling chain of the embodiment of the present invention integrates the deployment and locking into one mechanism, and adopts the motion chain 21 of the coupling metamorphic cell to switch the deformation state and the locking state. In the locked state, the motion chain 21 itself is used to carry the load to solve the high load-bearing problem of the locking mechanism, while avoiding the displacement fluctuation of the energy-type multi-stable structure under impact load and the unidirectional load-bearing problem of the contact metamorphic cell.

[0042] In some embodiments, in the same kinematic chain parallel unit 2, for the same kinematic chain 21, the first branch 211 includes a first rod member 2111, a second rod member 2112 and a third rod member 2113, one end of the first rod member 2111 is pivotally hinged to one of the corresponding two adjacent platforms 1, the other end of the first rod member 2111 is pivotally connected to one end of the second rod member 2112, the other end of the second rod member 2112 is pivotally connected to one end of the third rod member 2113, the other end of the third rod member 2113 is pivotally connected to the other platform 1 of the corresponding two adjacent platforms 1, one end of the second branch 212 is pivotally connected to the middle of the first rod member 2111, and the other end of the second branch 212 is pivotally connected to the middle of the third rod member 2113 of another kinematic chain 21. Thus, the kinematic chain 21 has a simple structure. Multiple kinematic chains 21 enable three-dimensional rotation of one platform 1 relative to the other platform 1 between two adjacent platforms 1. When a singular position occurs during the three-dimensional rotation of one platform 1 relative to the other platform 1 in each kinematic chain 21, the second branch 212 can lock the first branch 211 through its own local degree of freedom, thereby preventing relative motion between the two adjacent platforms 1. This achieves locking of the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism in a specific state. After locking, the first branch 211 and the second branch 212 in the kinematic chain 21 share the load. Therefore, the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism in this embodiment has higher load-bearing capacity after locking, while avoiding the displacement fluctuations of energy-type multistable structures under impact loads and the unidirectional load-bearing problems of contact metamorphic structures. The locked first branch 211 can also be unlocked through the local degree of freedom of the second branch 212, allowing one platform 1 of the two adjacent platforms 1 to rotate three-dimensionally relative to the other platform 1.

[0043] In some embodiments, the second branch chain 212 includes a fourth rod member 2121, a fifth rod member 2122, and a sixth rod member 2123. One end of the fourth rod member 2121 is pivotally connected to the middle portion of the first rod member 2111, the other end of the fourth rod member 2121 is pivotally connected to one end of the fifth rod member 2122, the other end of the fifth rod member 2122 is pivotally connected to one end of the sixth rod member 2123, and the other end of the sixth rod member 2123 is pivotally connected to the middle portion of the third rod member 2113 of another kinematic chain 21. Thus, the kinematic chain 21 has a simple structure, and multiple kinematic chains 21 can achieve three-dimensional rotation of one of two adjacent platforms 1 relative to the other platform 1.

[0044] When the kinematic chain 21 appears in a singular position, the pivot axis of one end of the second rod member 2112 is coaxial with the pivot axis of one end of the fifth rod member 2122, the pivot axis of the other end of the second rod member 2112 is coaxial with the pivot axis of the other end of the fifth rod member 2122, and the pivot axis of one end of the fourth rod member 2121 is coaxial with the pivot axis of the other end of the sixth rod member 2123. At this time, the second branch chain 212 can rotate around the coaxial pivot axis of one end of the fourth rod member 2121 and the other end of the sixth rod member 2123 (that is, the rotational freedom of the second branch chain 212 can be understood as the local freedom of the second branch chain or the kinematic chain). If the pivot axis of one end of the second rod member 2112 is coaxial with the pivot axis of one end of the fifth rod member 2122 If the end pivot axes are not coaxial and the pivot axis of one end of the fourth rod member 2121 is not coaxial with the pivot axis of the other end of the sixth rod member 2123, the second branch chain 212 locks the first branch chain 211, thereby preventing relative movement between the corresponding two adjacent platforms 1, so as to achieve the locking of a specific state of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of this embodiment, and after locking, the first branch chain 211 and the second branch chain 212 in the motion chain 21 jointly bear the load. Therefore, the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of this embodiment has higher load-bearing performance after locking, and at the same time avoids the displacement fluctuation of the energy-type multi-stable structure under impact load and the unidirectional load-bearing problem of the contact metamorphic cell. The first branch chain 211 in the locked state can also rotate around the coaxial pivot axis of one end of the fourth rod member 2121 and the other end of the sixth rod member 2123 through the second branch chain 212, so that the pivot axis of one end of the second rod member 2112 is coaxial with the pivot axis of one end of the fifth rod member 2122, and the pivot axis of the other end of the second rod member 2112 is coaxial with the pivot axis of the other end of the fifth rod member 2122, thereby enabling one platform 1 of the two corresponding adjacent platforms 1 to perform three-dimensional rotation relative to the other platform 1.

[0045] That is to say, in certain configurations, the locking three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of this embodiment has local degrees of freedom on the second branch 212. On the premise that the platform 1 is stationary, the second branch 212 is driven to rotate through the local degrees of freedom, thereby changing the constraint of the second branch 212 on the platform 1, so that the changed constraint plus the original constraint of the first branch 211 reach the full constraint condition, thereby realizing the locking of the locking three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the embodiment in certain configurations.

[0046] In some embodiments, the revolute pairs at both ends and the middle of the first rod member 2111 are skewed, the revolute pairs at both ends of the second rod member 2112 are skewed, the revolute pairs at both ends and the middle of the third rod member 2113 are skewed, the revolute pairs at both ends of the fourth rod member 2121 are skewed, the revolute pairs at both ends of the fifth rod member 2122 are skewed, and the revolute pairs at both ends of the sixth rod member 2123 are skewed. This facilitates the kinematic chain parallel unit 2 to achieve three-dimensional rotation of one of two adjacent platforms 1 relative to the other, and facilitates the kinematic chain 21 to achieve self-locking by utilizing singularity.

[0047] In some embodiments, for the same kinematic chain parallel unit 2, each of the two adjacent platforms 1 is provided with a plurality of mounting portions 11. The plurality of mounting portions 11 on one of the two adjacent platforms 1 are aligned one-to-one with the plurality of mounting portions 11 on the other platform 1. The ends of the plurality of first branch chains 211 are respectively connected to the plurality of mounting portions 11 on the two adjacent platforms 1. This facilitates installation between the first branch chains 211 and the platforms 1. Specifically, one end of the plurality of first rod members 2111 is connected one-to-one with the plurality of mounting portions 11 on one of the two adjacent platforms 1, and the other ends of the plurality of third rod members 2111 are connected one-to-one with the plurality of mounting portions 11 on the other platform 1.

[0048] In some embodiments, both ends of each first branch chain 211 are respectively connected to two adjacent diagonally opposite mounting portions 11 on two corresponding adjacent platforms 1. Thus, the layout of the kinematic chain 21 is reasonable.

[0049] In some embodiments, within the same kinematic chain 21, the second branch 212 is located outside the first branch 211. When the kinematic chain 21 reaches a singular position, the second branch 212 rotates outward or inward relative to the first branch 211 to lock the first branch 211. It should be noted that when the second branch 212 rotates outward relative to the first branch 211, collision and interference between the second branch 212 and the first branch 211 can be effectively avoided.

[0050] In some embodiments, the number of kinematic chains 21 in the kinematic chain parallel units 2 between two different adjacent platforms 1 may be the same or different, and may be selected according to actual needs.

[0051] In some embodiments, the platform 1 is a ring with a simple structure. It should be noted that the platform 1 may not be limited to a ring, but may also be a flat plate or a platform 1 of other shapes.

[0052] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0053] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain, characterized in that: include: Platform, there are multiple platforms, and the multiple platforms are arranged in sequence at intervals; A kinematic chain parallel unit, wherein the kinematic chain parallel units are connected one-to-one between two adjacent platforms, and each kinematic chain parallel unit is used to constrain the three-dimensional rotation of one of the corresponding two adjacent platforms relative to the other platform; each kinematic chain parallel unit includes a plurality of kinematic chains, and the plurality of kinematic chains respectively include a first branch chain and a second branch chain, a plurality of the first branches are connected in parallel to the two adjacent platforms at intervals along the circumferential direction, and a plurality of the second branches are sequentially connected one-to-one between the two adjacent first branches; in the same kinematic chain parallel unit, when a singular position occurs in each kinematic chain during the three-dimensional rotation of one of the corresponding two adjacent platforms relative to the other platform, the second branch chain can lock and unlock the first branch chain by using its own local degree of freedom; In the same kinematic chain parallel unit, for the same kinematic chain, the first branch comprises a first rod member, a second rod member and a third rod member, one end of the first rod member is pivotally hinged to one of the corresponding two adjacent platforms, the other end of the first rod member is pivotally connected to one end of the second rod member, the other end of the second rod member is pivotally connected to one end of the third rod member, the other end of the third rod member is pivotally connected to the other of the corresponding two adjacent platforms, one end of the second branch is pivotally connected to the middle of the first rod member, and the other end of the second branch is pivotally connected to the middle of the third rod member of the other kinematic chain; The second branch chain includes a fourth rod member, a fifth rod member, and a sixth rod member, one end of the fourth rod member is pivotally connected to the middle portion of the first rod member, the other end of the fourth rod member is pivotally connected to one end of the fifth rod member, the other end of the fifth rod member is pivotally connected to one end of the sixth rod member, and the other end of the sixth rod member is pivotally connected to the middle portion of the third rod member of the other kinematic chain; When the motion chain appears in a singular position, the pivot axis of one end of the second rod member is coaxial with the pivot axis of one end of the fifth rod member, the pivot axis of the other end of the second rod member is coaxial with the pivot axis of the other end of the fifth rod member, and the pivot axis of one end of the fourth rod member is coaxial with the pivot axis of the other end of the sixth rod member. At this time, the second branch chain can rotate around the coaxial pivot axis of one end of the fourth rod member and the other end of the sixth rod member. If the pivot axis of one end of the second rod member is not coaxial with the pivot axis of one end of the fifth rod member and the pivot axis of one end of the fourth rod member is not coaxial with the pivot axis of the other end of the sixth rod member, the second branch chain locks the first branch chain.

2. The lockable three-dimensional rotation metamorphic parallel mechanism based on coupling chain according to claim 1 is characterized in that: The rotation pairs at both ends and the middle of the first rod member are skewed from each other, the rotation pairs at both ends of the second rod member are skewed from each other, the rotation pairs at both ends and the middle of the third rod member are skewed from each other, the rotation pairs at both ends of the fourth rod member are skewed from each other, the rotation pairs at both ends of the fifth rod member are skewed from each other, and the rotation pairs at both ends of the sixth rod member are skewed from each other.

3. The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to any one of claims 1-2, characterized in that: As for the same motion chain parallel unit, the corresponding two adjacent platforms are respectively provided with multiple mounting parts, the multiple mounting parts on one of the corresponding two adjacent platforms are directly opposite to the multiple mounting parts on the other platform, and the two ends of the multiple first branches are respectively connected to the multiple mounting parts on the corresponding two adjacent platforms.

4. The lockable three-dimensional rotation metamorphic parallel mechanism based on coupling chain according to claim 3 is characterized in that: Both ends of each first branch chain are respectively connected to two adjacent diagonally opposite mounting portions on two corresponding adjacent platforms.

5. The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to any one of claims 1-2, characterized in that: In the same kinematic chain, the second branch is located outside the first branch; when the kinematic chain appears in a singular position, the second branch rotates outward or inward relative to the first branch to lock the first branch.

6. The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to any one of claims 1-2, characterized in that: The number of kinematic chains in the kinematic chain parallel units between two different adjacent platforms is the same or different.

7. The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to any one of claims 1-2, characterized in that: The platform is a ring body.

Images