Progressing beyond the stowage and deployment of reflectors and designing for multiple deployed states result in reflector shape reconfiguration,thus allowing for new functions including radiation pattern reconfigurat...Progressing beyond the stowage and deployment of reflectors and designing for multiple deployed states result in reflector shape reconfiguration,thus allowing for new functions including radiation pattern reconfiguration,and is valuable for space applications such as satellite-based radar and communications.This paper introduces a concept for achieving the deployment and shape reconfiguration of a paraboloid reflector using a 7R-8R(revolute joint)truss network.By realizing reconfigurability mechanically,complex electronic systems such as phased arrays can be avoided,and adopting a single-degree-of-freedom(DOF)design further reduces the number of required actuators.The proposed reflector is axisymmetric and can be doubly curved.It comprises a flexible mesh surface supported by a rigid truss network constructed from 7R and 8R linkages.Approximation of multiple target surfaces is achieved by synthesizing the truss network dimensions using a multiobjective optimization approach.The non-dominated sorting genetic algorithm is used in conjunction with analytical dimension parameterization and forward kinematics computation to determine the optimal dimensions for the truss network.In the resulting designs,the reflector follows a single-DOF trajectory,on which it unfolds from a compact stowed bundle toward a deployed state approximating a doubly curved target surface,then onwards to additional deployed states approximating different target surfaces.Design studies are conducted to demonstrate the reflector’s ability to approximate different target surfaces and continuously transform between such surfaces.This study proposes a new method for reconfiguring reflector shape mechanically,thus uniquely reconfiguring the shape of a doubly curved surface and achieving both deployment and shape reconfiguration under a unified single-DOF motion.展开更多
Space-deployable mechanisms can be used as supporting structures for large-diameter antennas in space engineering.This study proposes a novel method for constructing the surface design of space reflector antennas base...Space-deployable mechanisms can be used as supporting structures for large-diameter antennas in space engineering.This study proposes a novel method for constructing the surface design of space reflector antennas based on polar scissor units.The concurrency and deployability equations of the space scissor unit with definite surface constraints are derived using the rod and vector methods.Constraint equations of the spatial transformation for space n-edge polar scissor units are summarized.A new closed-loop deployable structure,called the polar scissor deployable antenna(PSDA),is designed by combining planar polar scissor units with spatial polar scissor units.The overconstrained problem is solved by releasing the curve constraint that locates at the end-point of the planar scissor mechanism.Kinematics simulation and error analysis are performed.The results show that the PSDA can effectively fit the paraboloid of revolution.Finally,deployment experiments verify the validity and feasibility of the proposed design method,which provides a new idea for the construction of large space-reflector antennas.展开更多
A 3D synchronism deployable antenna was designed, analyzed, and manufactured by our research group. This an-tenna consists of tetrahedral elements from central element. Because there are springs at the ends of some of...A 3D synchronism deployable antenna was designed, analyzed, and manufactured by our research group. This an-tenna consists of tetrahedral elements from central element. Because there are springs at the ends of some of the rods, spider joints are applied. For analysis purpose, the structure is simplified and modelled by using 2D beam elements that have no bending stiffness. Displacement vectors are defined to include two translational displacements and one torsional displacement. The stiff-ness matrix derived by this method is relatively simple and well defined. The analysis results generated by using software de-veloped by our research group agreed very well with available test data.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52320105005,52035008)the New Cornerstone Science Foundation through the Xplorer Prize(Grant No.XPLORER-2020-1035).
文摘Progressing beyond the stowage and deployment of reflectors and designing for multiple deployed states result in reflector shape reconfiguration,thus allowing for new functions including radiation pattern reconfiguration,and is valuable for space applications such as satellite-based radar and communications.This paper introduces a concept for achieving the deployment and shape reconfiguration of a paraboloid reflector using a 7R-8R(revolute joint)truss network.By realizing reconfigurability mechanically,complex electronic systems such as phased arrays can be avoided,and adopting a single-degree-of-freedom(DOF)design further reduces the number of required actuators.The proposed reflector is axisymmetric and can be doubly curved.It comprises a flexible mesh surface supported by a rigid truss network constructed from 7R and 8R linkages.Approximation of multiple target surfaces is achieved by synthesizing the truss network dimensions using a multiobjective optimization approach.The non-dominated sorting genetic algorithm is used in conjunction with analytical dimension parameterization and forward kinematics computation to determine the optimal dimensions for the truss network.In the resulting designs,the reflector follows a single-DOF trajectory,on which it unfolds from a compact stowed bundle toward a deployed state approximating a doubly curved target surface,then onwards to additional deployed states approximating different target surfaces.Design studies are conducted to demonstrate the reflector’s ability to approximate different target surfaces and continuously transform between such surfaces.This study proposes a new method for reconfiguring reflector shape mechanically,thus uniquely reconfiguring the shape of a doubly curved surface and achieving both deployment and shape reconfiguration under a unified single-DOF motion.
基金Supported by National Key R&D Program of China(Grant No.2018YFB1304600)National Natural Science Foundation of China(Grant No.51775541)+1 种基金CAS Interdisciplinary Innovation Team of China(Grant No.JCTD-2018-11)Hundred-Talent Program(Chinese Academy of Sciences)(Grant No.Y8A3210304).
文摘Space-deployable mechanisms can be used as supporting structures for large-diameter antennas in space engineering.This study proposes a novel method for constructing the surface design of space reflector antennas based on polar scissor units.The concurrency and deployability equations of the space scissor unit with definite surface constraints are derived using the rod and vector methods.Constraint equations of the spatial transformation for space n-edge polar scissor units are summarized.A new closed-loop deployable structure,called the polar scissor deployable antenna(PSDA),is designed by combining planar polar scissor units with spatial polar scissor units.The overconstrained problem is solved by releasing the curve constraint that locates at the end-point of the planar scissor mechanism.Kinematics simulation and error analysis are performed.The results show that the PSDA can effectively fit the paraboloid of revolution.Finally,deployment experiments verify the validity and feasibility of the proposed design method,which provides a new idea for the construction of large space-reflector antennas.
基金Project (No. 863-2-4) supported by the National Basic Research Program (863) of China
文摘A 3D synchronism deployable antenna was designed, analyzed, and manufactured by our research group. This an-tenna consists of tetrahedral elements from central element. Because there are springs at the ends of some of the rods, spider joints are applied. For analysis purpose, the structure is simplified and modelled by using 2D beam elements that have no bending stiffness. Displacement vectors are defined to include two translational displacements and one torsional displacement. The stiff-ness matrix derived by this method is relatively simple and well defined. The analysis results generated by using software de-veloped by our research group agreed very well with available test data.
