农业机械学报2017，Vol.48Issue(12)：395-402,8.DOI:10.6041/j.issn.1000-1298.2017.12.049
12-6台体型Stewart冗余并联机构正向运动学研究
Forward Kinematics of General 12-6 Stewart Redundant Parallel Mechanism
摘要
Abstract
Aiming at the present situation that forward kinematics of most 6-DOF (degrees of freedom) parallel mechanisms cannot be described with whole analytical solutions,and a very few of them can be described with whole analytical solutions but also with these difficulties,including calculation,programming,and sorting the suitable solution,a general 12-6 Stewart redundant parallel mechanism with hybrid single opened chains was presented,and a whole analytical decoupling algorithm of forward kinematics,which was needed by the closed-loop real-time feedback control system,was constructed.By calculating the position and orientation characteristics set and decomposing the routes of single opened chains,the topological configuration of new mechanism was analyzed,and then the coupling degrees was solved,which were useful to show clearly direction to construct and process the kinematics equations.Based on the topological relations between four coplanar feature points on the moving platform,the combination algorithms of 15 quadratic isomorphic compatible equations were designed,and then the whole analytical solution,which was succinct,symmetric and unique,of forward displacement equations was derived.Based on the method of base points,velocity relations between feature points were established,and then forward velocity equations were solved.Based on compatibility equations and velocity equations,the Jacobian matrix of mechanism was derived,and then three types of singular equations were also derived.Experimental results indicated that the calculated values of forward displacement equations were well consistent with the measured values,and calculation error of forward velocity equations was 0.08％,and the calculation/sampling time ratios of these two equations were 0.21 and 0.32,respectively,which met the real-time demand of control algorithms.关键词
并联机构/运动学正解/解析算法/实时性/雅可比矩阵Key words
parallel mechanism/forward kinematics/analytical algorithm/real time/Jacobian matrix分类
机械制造引用本文复制引用
尤晶晶,符周舟,吴洪涛,李成刚,周为..12-6台体型Stewart冗余并联机构正向运动学研究[J].农业机械学报,2017,48(12):395-402,8.基金项目
国家自然科学基金项目(51405237)、江苏省精密与微细制造技术重点实验室开放基金项目、南京林业大学高学历人才基金项目(GXL2014045)和江苏省高等学校大学生创新创业训练计划项目(201710298012Z) （51405237）
