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

Abstract

The invention discloses a lockable three-dimensional rotating metamorphic parallel mechanism based on a coupling chain, and the lockable three-dimensional rotating metamorphic parallel mechanism is characterized in that a plurality of platforms are sequentially arranged at intervals; the kinematic chain parallel connection units are correspondingly connected between every two adjacent platforms to restrain three-dimensional rotation of one of the two corresponding adjacent platforms relative to the other platform; each kinematic chain parallel unit comprises a plurality of kinematic chains, each kinematic chain comprises a first branch chain and a second branch chain, the first branch chains are connected to the two adjacent platforms in parallel, and the second branch chains are sequentially and correspondingly connected between every two adjacent first branch chains; in the same kinematic chain parallel connection unit, when each kinematic chain is in a singular position, the second branch chain can lock and unlock the first branch chain through the local degree of freedom of the second branch chain. The problem of high bearing capacity of a locking mechanism can be solved, and meanwhile, the problems of displacement fluctuation of an energy type multistable structure under an impact load and one-way bearing of contact metamorphism are avoided.

Description

Technical Field

[0001] The 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] Deployment structures are widely used in the fields of industry, medical treatment, exploration, etc. Their advantages are the easy-to-place contracted state, the deployed state that can adapt to different requirements, and the deployment process with a controllable path. After the deployment structure is deformed, it needs to resist the load through a locking design to maintain its shape. Traditional locking designs usually design additional locking mechanisms on the existing deployment structure, such as locking the movable joints of the mechanism through latches, mast component tracks, barb grooves, spring devices, etc., which reduces the degree of freedom and achieves the locking of the overall structure.

[0003] Among the multi-stable structural designs that combine deployment and locking, energy-type and contact morphing multi-stable structures are the main ones. Energy-type multi-stable structures rely on the minimum value of potential energy in a specific posture to achieve locking. The existing energy storage structures are bending beams, springs, electromagnets, and origami structures. Contact morphing relies on changing the contact surface or interaction force between them, thereby changing the overall topological structure to achieve locking. The very few designs that utilize the singularity of the mechanism are concentrated on Bricard-like single rings and universal hinges, and are usually not suitable for locking.

[0004] The traditional locking mechanism is an additional mechanism designed on the basis of the unfolding structure. Since it is a limit lock for the movable joint, it will increase the overall floating mass, thereby increasing the requirements for driving power. At the same time, the track in the locking mechanism limits the freedom of the mechanism and reduces the flexibility of the unfolding. In addition, the mechanism that changes the joint from movable to locked will also become the most important load-bearing structure, and the strength requirements of the locking mechanism are high.

[0005] Although the energy-type multistable structure can bear loads by itself, the output platform will experience displacement fluctuations when facing sudden or periodic loads, and it is not applicable when facing situations where deformation needs to be maintained. Although the contact cell has no displacement fluctuations, it can only bear unidirectional loads. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to propose a lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain, which can perform three-dimensional rotation deformation and locking, solve the high load-bearing problem of the locking mechanism, and avoid the displacement fluctuation of the energy-type multi-stable structure under impact load and the unidirectional load-bearing problem of the contact metamorphic cell.

[0007] The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to an embodiment of the present invention comprises: A platform, wherein there are a plurality of the platforms, and the plurality of the platforms are arranged in sequence and 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, and the plurality of first branches are connected in parallel to the two adjacent platforms at intervals along the circumferential direction, and the plurality of second branches are connected one-to-one between the two adjacent first branches in sequence; 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.

[0008] According to the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism of an embodiment of the present invention, a motion chain parallel unit is arranged 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, and 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 in sequence. The motion chain parallel unit of this structure can realize the three-dimensional rotation of one platform of the corresponding two adjacent platforms relative to the other platform. In the same kinematic chain parallel unit, when each kinematic chain has a singular position during the three-dimensional rotation of one of the two corresponding adjacent platforms relative to the other platform, the second branch chain can lock the first branch chain through its own local degree of freedom, thereby preventing the two corresponding adjacent platforms from relative movement. Thus, 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 chain and the second branch chain in the kinematic chain jointly bear 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 cell. The first branch chain in the locked state can also be unlocked through the local degree of freedom of the second branch chain, so that one of the two corresponding adjacent platforms can perform three-dimensional rotation relative to the other platform.

[0009] The lockable three-dimensional rotating metamorphic parallel mechanism based on a coupling chain in an embodiment of the present invention integrates deployment and locking into one mechanism, and adopts a motion chain form of a coupled metamorphic cell to switch between the deformation state and the locking state. In the locked state, the motion chain itself carries 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.

[0010] In some embodiments, in the same parallel unit of the kinematic chain, for the same kinematic chain, the first branch chain 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 chain is pivotally connected to the middle part of the first rod member, and the other end of the second branch chain is pivotally connected to the middle part of the third rod member of the other kinematic chain.

[0011] 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 another of the kinematic chains; When a singular position appears in the motion chain, the pivot axis at one end of the second rod member is coaxial with the pivot axis at one end of the fifth rod member, the pivot axis at the other end of the second rod member is coaxial with the pivot axis at the other end of the fifth rod member, and the pivot axis at one end of the fourth rod member is coaxial with the pivot axis at the other end of the sixth rod member. At this time, the second branch chain can rotate around the coaxial pivot axis between one end of the fourth rod member and the other end of the sixth rod member. If the pivot axis at one end of the second rod member is not coaxial with the pivot axis at one end of the fifth rod member and the pivot axis at one end of the fourth rod member is not coaxial with the pivot axis at the other end of the sixth rod member, the second branch chain locks the first branch chain.

[0012] In some embodiments, the rotation pairs at both ends and the middle part 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 part 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.

[0013] 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 branch chains are respectively connected to the multiple mounting parts on the corresponding two adjacent platforms.

[0014] In some embodiments, two ends of each of the first branch chains are respectively connected to two adjacent diagonally opposite mounting portions on two corresponding adjacent platforms.

[0015] 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.

[0016] 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.

[0017] In some embodiments, the platform is a ring.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 It is a front view of the lockable three-dimensional rotating metamorphic parallel mechanism based on the coupling chain of the present invention; Figure 2 It is a front view of the first branch chain of the lockable three-dimensional rotating metamorphic parallel mechanism based on the coupling chain of the present invention; Figure 3 It is a left view of the first branch chain of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention; Figure 4 It is a front view of the second branch chain of the lockable three-dimensional rotating metamorphic parallel mechanism based on the coupling chain of the present invention; Figure 5 It is a left view of the second branch chain of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention; Figure 6 It is a schematic diagram of the deformation state of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention; Figure 7It is a schematic diagram of the locked state of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention; Figure 8 It is a schematic diagram of the positional relationship between the second branch chain and the first branch chain 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; Fig. 9 It is a schematic diagram of the second branch chain morphology in the locked state of the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of the present invention.

[0020] Reference numerals: 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; sixth rod member 2123. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which 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 only used to explain the present invention, and cannot be understood as limiting the present invention.

[0022] Combine the following Figures 1 to 9 To describe the lockable three-dimensional rotational metamorphic parallel mechanism based on a coupling chain according to an embodiment of the present invention.

[0023] like Figures 1 to 9 As shown, the lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to an embodiment of the present invention includes a platform 1 and a kinematic chain parallel unit 2.

[0024] 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 1 It is shown that three platforms 1 are arranged at intervals in the up and down directions.

[0025] The kinematic chain parallel units 2 are connected one by one between two adjacent platforms 1, that is, one kinematic chain parallel unit 2 is arranged between each two adjacent platforms 1. Each kinematic chain parallel unit 2 is used to constrain the three-dimensional rotation of one platform 1 of the corresponding two adjacent platforms 1 relative to the other platform 1, that is, the three-dimensional rotation range of one platform 1 of the two adjacent platforms 1 relative to the other platform 1 is controlled by setting the kinematic chain parallel unit 2.

[0026] Each kinematic chain parallel unit 2 includes a plurality of kinematic chains 21, each of which includes a first branch chain 211 and a second branch chain 212. The plurality of first branch chains 211 are connected in parallel to two adjacent platforms 1 at intervals along the circumferential direction, and the plurality of second branch chains 212 are connected one by 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 lock and unlock the first branch chain 211 by using its own local degree of freedom. In detail, when the kinematic chain 21 appears a singular position during the three-dimensional rotation of one of the two corresponding adjacent platforms 1 relative to the other platform 1, the second branch chain 212 can lock the first branch chain 211 through its own local degree of freedom, thereby preventing the two corresponding adjacent platforms 1 from relative movement. Thus, 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 chain 211 and the second branch chain 212 in the kinematic chain 21 jointly bear 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 chain 211 in the locked state can also be unlocked through the local degree of freedom of the second branch chain 212, so that one of the two corresponding adjacent platforms 1 can rotate three-dimensionally relative to the other platform 1.

[0027] According to the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism of an embodiment of the present invention, a motion chain parallel unit 2 is arranged 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, and the multiple first branch chains 211 are connected in parallel between the corresponding two adjacent platforms 1 at intervals along the circumferential direction, and the multiple second branch chains 212 are connected one by one between the two adjacent first branch chains 211 in sequence. The motion chain parallel unit 2 of this structure can realize the three-dimensional rotation of one platform 1 of the corresponding two adjacent platforms 1 relative to the other platform 1. In the same kinematic chain parallel unit 2, when each kinematic chain 21 has 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 chain 212 can lock the first branch chain 211 through its own local degree of freedom, so that the two corresponding adjacent platforms 1 cannot move relative to each other. Thus, 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 realized, and after locking, the first branch chain 211 and the second branch chain 212 in the kinematic chain 21 jointly bear 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, 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 be unlocked through the local degree of freedom of the second branch chain 212, so that one of the corresponding two adjacent platforms 1 can rotate three-dimensionally relative to the other platform 1.

[0028] The coupled chain-based lockable three-dimensional rotational metamorphic parallel mechanism of the embodiment of the present invention integrates deployment and locking into one mechanism, and adopts a motion chain 21 of a coupled metamorphic cell to switch between the deformation state and the locking state. In the locked state, the motion chain 21 itself carries 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.

[0029] In some embodiments, in the same motion chain parallel unit 2, for the same motion chain 21, the first branch chain 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 chain 212 is pivotally connected to the middle part of the first rod member 2111, and the other end of the second branch chain 212 is pivotally connected to the middle part of the third rod member 2113 of another motion chain 21. Thus, the kinematic chain 21 has a simple structure, and a plurality of kinematic chains 21 can realize a three-dimensional rotation of one of the two adjacent platforms 1 relative to the other platform 1. When a singular position appears in each kinematic chain 21 during the three-dimensional rotation of one of the two adjacent platforms 1 relative to the other platform 1, the second branch chain 212 can lock the first branch chain 211 through its own local degree of freedom, thereby preventing the two adjacent platforms 1 from relative motion, so as to realize 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 kinematic chain 21 jointly bear the load, so that the lockable three-dimensional rotation metamorphic parallel mechanism based on the coupling chain of this embodiment has a 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 be unlocked through the local degree of freedom of the second branch chain 212, so that one of the two adjacent platforms 1 can perform a three-dimensional rotation relative to the other platform 1.

[0030] 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 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 of the third rod member 2113 of another kinematic chain 21. Thus, the kinematic chain 21 has a simple structure, and a plurality of kinematic chains 21 can realize a three-dimensional rotation of one of two adjacent platforms 1 relative to the other platform 1.

[0031] When the kinematic chain 21 appears in a singular position, the pivot axis at one end of the second rod member 2112 is coaxial with the pivot axis at one end of the fifth rod member 2122, the pivot axis at the other end of the second rod member 2112 is coaxial with the pivot axis at the other end of the fifth rod member 2122, and the pivot axis at one end of the fourth rod member 2121 is coaxial with the pivot axis at the other end of the sixth rod member 2123. At this time, the second branch chain 212 can rotate around the coaxial pivot axis between 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 at one end of the second rod member 2112 is coaxial with the pivot axis at 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, so that relative movement cannot occur between the corresponding two adjacent platforms 1, so as to realize the locking of a specific state of the lockable three-dimensional rotating 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 rotating 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 be rotated 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 of the two corresponding adjacent platforms 1 to perform three-dimensional rotation relative to the other platform 1.

[0032] That is to say, in certain configurations, the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism of this embodiment has local degrees of freedom on the second branch chain 212. On the premise that the platform 1 remains stationary, the second branch chain 212 is driven to rotate through the local degrees of freedom, thereby changing the constraint of the second branch chain 212 on the platform 1, so that the changed constraint plus the original constraint of the first branch chain 211 reach the full constraint condition, thereby realizing the locking of the coupling chain-based lockable three-dimensional rotation metamorphic parallel mechanism of the embodiment in certain configurations.

[0033] In some embodiments, the rotation pairs at both ends and the middle of the first rod member 2111 are out of plane with each other, the rotation pairs at both ends of the second rod member 2112 are out of plane with each other, the rotation pairs at both ends and the middle of the third rod member 2113 are out of plane with each other, the rotation pairs at both ends of the fourth rod member 2121 are out of plane with each other, the rotation pairs at both ends of the fifth rod member 2122 are out of plane with each other, and the rotation pairs at both ends of the sixth rod member 2123 are out of plane with each other. Thus, it is beneficial for the kinematic chain parallel unit 2 to realize the three-dimensional rotation of one platform 1 of the two adjacent platforms 1 relative to the other platform 1, and it is beneficial for the kinematic chain 21 to use singularity for self-locking.

[0034] In some embodiments, for the same kinematic chain parallel unit 2, the corresponding two adjacent platforms 1 are respectively provided with a plurality of mounting portions 11, the plurality of mounting portions 11 on one of the corresponding two adjacent platforms 1 are directly opposite to the plurality of mounting portions 11 on the other platform 1, and the two ends of the plurality of first branch chains 211 are respectively connected to the plurality of mounting portions 11 on the corresponding two adjacent platforms 1. Thus, the first branch chains 211 are conveniently installed with the platform 1. Specifically, one end of the plurality of first rod members 2111 is connected to the plurality of mounting portions 11 on one of the corresponding two adjacent platforms 1 in a one-to-one correspondence, and the other end of the plurality of third rod members 2111 is connected to the plurality of mounting portions 11 on the other of the corresponding two adjacent platforms 1 in a one-to-one correspondence.

[0035] 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.

[0036] In some embodiments, in the same kinematic chain 21, the second branch chain 212 is located outside the first branch chain 211; when the kinematic chain 21 appears in a singular position, the second branch chain 212 rotates outward or inward relative to the first branch chain 211 to lock the first branch chain 211. It should be noted that when the second branch chain 212 rotates outward relative to the first branch chain 211, collision and interference between the second branch chain 212 and the first branch chain 211 can be effectively avoided.

[0037] In some embodiments, the number of kinematic chains 21 in the kinematic chain parallel unit 2 between two different adjacent platforms 1 may be the same or different, and may be selected according to actual needs.

[0038] In some embodiments, the platform 1 is a ring body with a simple structure. It should be noted that the platform 1 may not be limited to a ring body, but may also be a flat plate or a platform 1 of other shapes.

[0039] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0040] Although the 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 present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A lockable three-dimensional rotational metamorphic parallel mechanism based on a coupling chain, characterized in that: include: A platform, wherein there are a plurality of the platforms, and the plurality of the platforms are arranged in sequence and 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, and the plurality of first branches are connected in parallel to the two adjacent platforms at intervals along the circumferential direction, and the plurality of second branches are connected one-to-one between the two adjacent first branches in sequence; 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.

2. The lockable three-dimensional rotation metamorphic parallel mechanism based on coupling chain according to claim 1 is characterized in that: In the same kinematic chain parallel unit, for the same kinematic chain, the first branch chain 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 chain is pivotally connected to the middle part of the first rod member, and the other end of the second branch chain is pivotally connected to the middle part of the third rod member of the other kinematic chain.

3. The lockable three-dimensional rotation metamorphic parallel mechanism based on coupling chain according to claim 2 is characterized in that: The second branch chain comprises 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 another of the kinematic chains; When a singular position appears in the motion chain, the pivot axis at one end of the second rod member is coaxial with the pivot axis at one end of the fifth rod member, the pivot axis at the other end of the second rod member is coaxial with the pivot axis at the other end of the fifth rod member, and the pivot axis at one end of the fourth rod member is coaxial with the pivot axis at the other end of the sixth rod member. At this time, the second branch chain can rotate around the coaxial pivot axis between one end of the fourth rod member and the other end of the sixth rod member. If the pivot axis at one end of the second rod member is not coaxial with the pivot axis at one end of the fifth rod member and the pivot axis at one end of the fourth rod member is not coaxial with the pivot axis at the other end of the sixth rod member, the second branch chain locks the first branch chain.

4. The lockable three-dimensional rotation metamorphic parallel mechanism based on coupling chain according to claim 3 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.

5. The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to any one of claims 1 to 4, 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 branch chains are respectively connected to the multiple mounting parts on the corresponding two adjacent platforms.

6. The lockable three-dimensional rotation metamorphic parallel mechanism based on coupling chain according to claim 5, characterized in that: Both ends of each of the first branch chains are respectively connected to two adjacent diagonally opposite mounting portions on two corresponding adjacent platforms.

7. The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to any one of claims 1 to 4, characterized in that: In the same kinematic chain, the second branch chain is located outside the first branch chain; when the kinematic chain appears in a singular position, the second branch chain rotates outward or inward relative to the first branch chain to lock the first branch chain.

8. The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to any one of claims 1 to 4, characterized in that: The number of kinematic chains in the kinematic chain parallel units between two different adjacent platforms may be the same or different.

9. The lockable three-dimensional rotation metamorphic parallel mechanism based on a coupling chain according to any one of claims 1 to 4, characterized in that: The platform is a ring.

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