尺度约束类型是指构件为其所连接的运动副轴线之间的相对方位提供的几何约束类型,研究了一种基于尺度约束类型及其顺序的机器人支链的拓扑结构表示及其设计方法。建立尺度约束类型与符号表示之间的对应关系;基于方位特征集及自由度,将尺度约束类型作为单元,综合出4自由度和5自由度的串联机构结构,并给出其尺度约束类型表示;通过对6自由度关节机器人进行演化分析,获得5轴及4轴工业机器人,并对这些串联机器人的方位特征集及尺度约束类型进行分析。
The dimension constraint type refers to the geometric constraint type of the relative orientation between axes of kinematic pairs provided by the components. This paper proposed the representation method and design method of the topological structure of the robot branched chain based on dimension constraint type and order of the mechanism. Firstly, we give the definition of six basic kinds of dimension constraint type, which connected with the type of kinematic pair and the connection relationship of adjacent component are called the three elements of the topological structure. Then we establish the corresponding relationships between the dimension constraint types and symbolic representations of the components. Taking the dimension constraint type as a unit, then make structure synthesis of the serial mechanisms with 4 and 5 degrees of freedom (DOF) based on the degrees of freedom and position and orientation characteristic (POC) set which is used to describe the orientation characteristics of the relative movements of any two components of a mechanism. We also give the dimension constraint types of the above 4- DOF and 5- DOF serial mechanisms. We analyze the mechanism evolutions of the typical 6-DOF joint robot, and design the 5 joints and 4 joints industrial robots based on the mechanism evolution analysis. Finally, analyze the position and orientation characteristic (POC) sets and dimension constraint types of these serial robots.