中文摘要：

针对3-PPR并联机构位置正解问题,运用螺旋理论计算其自由度,并分析其运动特性,同时通过解析法构建该并联机构的完整运动学逆解。将并联机构运动学正解问题的求解转化为对目标函数优化问题的求解,并基于此建立该并联机构正解的目标函数优化模型。通过对基本蚁群算法进行有效的改进,构建了可用于求解连续优化问题的改进蚁群算法。运用该算法求解3-PPR并联机构的运动学正解并进行Matlab仿真分析,对比传统数值方法和改进蚁群算法,证实该算法具有良好的全局寻优能力,并能避免初值和局部最优值对计算结果的影响,可有效应用于求解并联机构的位置正解问题。

英文摘要：

Based on the screw theory,the degree of freedom of the 3-PPR parallel mechanism was computed,also the kinetic characteristic was analyzed according to its structural features,and the integrated inverse kinematics was established based on the analytic method. In order to solve the problem of parallel mechanism forward kinematics,this paper proposed a method that translated this problem into objective function optimization,and also built its mathematical model. By improving the basic ant colony algorithm effectively,an ACA was developed for solving the continuous optimization problem. Then this method was used to solve the forward kinematics problem of the 3-PPR parallel mechanism,and it was put into simulation by Matlab. Compared with traditional numerical method,this improved ACA was better at global optimization,and it could avoid the unfavorable effects caused by initial values,so did the local optimal values,also the calculation process will be much simpler without solving the Jacobian matrix and its inverse matrix. Then it is proved that this method is useful for solving the forward kinematics of common parallel mechanisms.