摘要
为提升并联机构的运动学与静力学综合性能,提出了一种基于空间模型技术的并联机构多目标尺度参数优化方法。首先,根据人机工程学设计了一种2-PUS/RS三自由度并联机构,并基于螺旋理论分析了机构2种类型支链的自由度,计算了并联机构的自由度;采用欧拉角描述了动平台姿态,推导了机构的位置反解;在肘、腕关节的转动副和驱动器约束条件下,利用搜索法得到了机构的工作空间;然后,定义了角速度传递、角速度各向同性性能评价指标,绘制了评价指标在工作空间中的等高线分布图;最后,利用空间模型技术无量纲化尺度参数,绘制了各项全域性能图谱,并采用加权求和法对其进行了多目标参数优化,得到了机构的最优结构参数。研究结果表明:优化后机构的各项指标大幅提升,全域角速度传递性能、力矩传递性能和各向同性性能分别提高了16%、80%、40%,验证了该尺度参数优化方法的有效性。
To improve the comprehensive performance of kinematics and statics for the parallel mechanism,based on spatial model technology,a multi-objective scale parameter optimization method for parallel mechanisms was proposed.Firstly,according to ergonomics,a three degree of freedom parallel structure 2-PUS/PRRRS was designed.Based on the screw theory,two types of branch degrees of freedom(DOF)were analyzed,and the degrees of freedom of parallel mechanism were calculated.The Euler angles were used to describe the posture of the moving platform,and the inverse position solution of the mechanism was deduced.Under the constraints of the revolution pair and driver of the elbow and wrist joints,the workspace of the mechanism was obtained by using the search method.Then,the performance evaluation indexes of angular velocity transmission and angular velocity isotropy were defined,and the contour map of evaluation indexes in the workspace was plotted.Finally,the spatial model technology was used to dimensionless the scale parameters,various global performance maps were drawn,and the optimal structural parameters were obtained by using the weighted summation method to optimize the multi-objective parameters.The results show that the global angular velocity transmission performance,torque transfer performance and isotropic performance of the optimized mechanism are increased by 16%,80% and 40% respectively,and the effectiveness of the optimization method is verified via the significant improvement of various indexes.
作者
罗怡沁
吕兴荣
LUO Yi-qin;LV Xing-rong(School of Mechanical,Electrical and Rail Transit,Zhejiang Fashion Institute of Technology,Ningbo 315211,China)
出处
《机电工程》
CAS
北大核心
2021年第10期1340-1347,1360,共9页
Journal of Mechanical & Electrical Engineering
基金
浙江省高等教育“十三五”第二批教学改革研究资助项目(JG20190842)。
关键词
并联机构
尺度参数优化
运动学分析
螺旋理论
性能分析
parallel mechanism
optimization of scale parameters
kinematic analysis
screw theory
performance analysis
