Design And Analysis Of A Planar Bi-directional Spreading Antenna Support Mechanism

Planar deployable antennas are an important branch of space deployable antennas.With the complexity and diversification of space missions,planar deployable antennas are required to have larger physical apertures.In this paper,firstly,a bi-directional flat plate unfolding unit mechanism is proposed to realize the bi-directional unfolding of flat plate.And according to the design requirements of nine-grid flat antenna,an equivalent hinge link mechanism is designed instead of rotating hinge,and the bi-directional flat plate expandable unit mechanism is optimally applied to nine-grid flat antenna.On this basis,the kinematic analysis of the two mechanisms is carried out;the dynamics simulation and finite element analysis of the nine-grid flat antenna unfolding mechanism are carried out,and the rod dimensions are optimized,and the principle prototype is made based on the optimized results to verify the feasibility of the unfolding principle.Propose two kinds of planar bi-directional expandable mechanism,and analyze its unfolding principle and motion law.The degrees of freedom are calculated,and the appropriate drive subsets are selected to add positions,and the kinematic models of the two expandable mechanisms are established based on the closed-loop vector method.Through MATLAB software programming,the kinematic characteristics of the expandable mechanism during the unfolding process are analyzed,namely the mechanism unfolding bit shape diagram,the key node unfolding motion trajectory diagram,and the angle,angular velocity and angular acceleration change curves of each rod,and the conditions of the mechanism generating singularity are analyzed.Without considering gravity and springs,the dynamics model of the nine-lattice flat antenna expandable mechanism is established according to Lagrange’s equation.The three-dimensional models of the two spreading mechanisms are established in Solid Works,and the kinematic simulation is carried out by using Adams simulation software to verify the correctness of the theoretical kinematic model and obtain the relevant motion parameters during the unfolding of the mechanism;the dynamics simulation of the spreading mechanism of the nine-pattern flat antenna is carried out by using Adams simulation software to verify the correctness of the theoretical dynamics model.The modal analysis of the nine-pattern flat antenna is carried out by using ANSYA finite element software.Based on the response surface analysis method,the total mass and first-order intrinsic frequency and shape variables of the nine-pattern flat antenna are used as the optimization objectives and constraints to optimize the inner and outer diameters of the support rod of the nine-pattern flat antenna,and a set of optimization results with high first-order intrinsic frequency and light mass are obtained.And this dimension is used as the basis to complete the principle prototype development and verify the feasibility of the unfolding principle.