Design Method and Analysis of Point Surface Equivalent Coupling Mechanism Based on Regular Polyhedra
Based on the five structural characteristics of regular polyhedra,a design method for a point surface equivalent coupling mechanism is proposed.Firstly,by studying the structural characteristics of regular polyhedra in space,the moving and fixed platforms are selected,and the optimal axis of symmetry is chosen.Then,type Ⅰ and type Ⅱ coupling vertices are defined respectively.And various coupling branches are formed by sequentially connecting the type Ⅰ coupling vertices and the type Ⅱ coupling vertices together.Secondly,replacement components for geometric elements are designed.According to the principle of substitution,the type Ⅰ coupling vertices and the type Ⅱcoupling vertices can be replaced by regular polygons,while each edge in the coupling framework can be replaced by two auxiliary rods.The basic model of the coupling mechanism is formed by connecting the replacement components of regular polygons and the replacement components of two pairs of rods through the use of rotating pairs(R pairs),and the two end axes of R pairs are parallel to each other.Additionally,the maneuverability of the synthesized coupling mechanism is determined.Finally,the replacement components of the first and second types of coupling vertices are extended from regular polyhedra to non-regular polyhedra,and a quasi-icosahedral coupling mechanism is designed.And the motion trajectory of its moving platform is analyzed.
NETL
NSTL
万方数据
