对称结构Stewart 并联机器人的位置正解及构型分析

对具有对称结构的6－6SPSStewart并联机器人的位置正解问题进行了研究，以活动平台的铰链坐标为未知量，按定杆长约束条件建立了对称并联机器人位置正解的数学模型；以结构参数和杆长为量作为修正变量，构造了一种新的系数同伦方程，运用该方法可以快速得到同类并联机器人的全部28组位置正确。这种方法可以方便地求出不同结构参数和杆长变量同类机构的位置正解，其数学模型简单，并且不依赖初值。基于位置正解对Stewart并联机器人存在的装配构型进行了分析，给出了数值计算实例。

Direct Displacement and Configuration Analyses of Symmetrical Stewart Platform Mechanisms

The direct displacement analysis problem is as the application foundation for parallel mechanisms. Most of the parallel mechanisms in practice are symmetrical. In this paper, a direct displacement analysis method of symmetrical 6-6 SPS Stewart platform mechanisms is presented. According to restraints given by constant-length of link, the mathematical model is constructed with coordinates of joint center as variables with structure parameters and link variables being modified variables, a set of new equations are set up. The 28 solutions can be obtained with this method. This method can be used efficiently in homogeneous mechanisms with different structure parameters and different link variables. This method is simple and does not rely on initial values. The actual configuration analyses of symmetrical Stewart platform mechanisms are completed and a numerical example is given.