一种径向可展开机构的结构及运动学分析

根据一种径向可展开平面多杆机构的结构几何关系，推导了成角构件组成的剪式单元铰接点的轨迹方程，分析了铰接点沿径向运动时剪式单元中的结构约束条件，建立了剪式结构单元的运动学方程．然后采用坐标变换方法建立了可展开机构展开过程的运动学模型，揭示了这种可展开机构一些新的特性，包括最大展开范围条件和成角构件结构间的关系．通过分析机构中所有铰接点均沿径向运动的特例，建立了多层可展开机构的结构关系及运动学模型．仿真实例表明了该运动学分析的正确性．

Structure and kinematic analysis of radially deployable planar linkages

Based on the structural geometrical connections of a radially foldable planar linkage, the locus of the hinged points in a scissor-like unit composed of angulated elements is derived, the structural constrained conditions of the scissor-like unit are discussed when the hinged points move radially. Then we present the kinematic equations of two inter-connected angulated elements and establish the kinematic model of deployment for foldable linkages using the method of coordinate transformation. Some new properties of this radially foldable linkages are revealed, including the condition for the maximum deployed extension and the angulated relationship between two inter-connected elements. And we have established the structure connections and kinematic model of multilayer deployable linkages by discussing the special case of all the hinged points in the deployable linkage moving radially. Finally, simulation examples verify the effectiveness of the kinematics analysis method.