中文摘要：

获得大工作空间是并联机构设计中的一个重要目标,利用3种优化算法对并联机构工作空间体积进行优化,以6自由度机构6-RSS为例,建立优化模型,分析比较优化算法的性能。考察的性能指标主要有优化效果、数值稳定性、时间效率。涉及到的优化算法包括多岛遗传算法、广义简约梯度法、序列二次规划法,后两种算法在应用时与试验设计（Design of experiment,DOE）方法进行集成。试验分析表明,DOE结合局部优化算法的改进型优化方法有明显优势,优化后6-RSS并联机构的工作空间体积增加为原来的2.59倍,优化时间仅为多岛遗传算法的1/5,优化结果稳定。

英文摘要：

Large workspace is an important target in parallel mechanism design.The application of three optimization algorithms in the workspace optimization of parallel mechanisms is studied by taking a 6-RSS parallel mechanism of 6 DOFs as example.The optimization model is established.Then the performances of the optimization algorithms are analyzed and compared,and the main investigated performance indexes are optimization results,numerical stability and time efficiency.The optimization algorithms concerned are multi-island genetic algorithm（MIGA）,generalized reduced gradient method and sequential quadratic programming method,and the latter two in application are respectively integrated with design of experiment（DOE） method.The experimental analysis shows that local optimization algorithms integrated with DOE has obvious advantage that the workspace volume of the 6-RSS parallel mechanism increases to 2.59 times that of the original one,the time taken for optimization is only 1/5 that of MIGA,and the optimization result is stable.