摘要
根据基于方位特征方程的并联机构拓扑设计理论和方法,设计、分析了一种零耦合度且部分运动解耦的三自由度非对称两平移一转动(2T1R)并联机构,包括:给出机构的拓扑设计过程,计算其自由度、耦合度κ等主要拓扑特性;其次,基于拓扑特征运动学建模方法,求出其符号式位置正反解,并通过正解进行工作空间计算;同时导出位置逆解方程,得到动平台雅可比矩阵,由此导出机构内各构件的速度、加速度以及奇异性;又运用基于虚功原理的序单开链法进行逆向动力学建模,得到该机构主动副的驱动力变化曲线,同时以子运动链(SKC)为单元,求解SKC连接处运动副的支反力,并通过ADAMS予以动力学仿真验证。最后,分析了该机构可用作不同高度输送带之间物料自动转运、卸料装置的潜在应用场景,并给出了其概念设计。本文为两支链大转角并联机构的高效运动学、动力学建模与分析,以及机构性能优化与样机研发提供了理论依据。
According to the theory and method of topological structure design of parallel mechanism(PM) based on position and orientation characteristic(POC) equation,a 3-DOF asymmetric two-translation and one-rotation(2T1R) PM with zero coupling-degree and partial motion decoupling was firstly designed and analyzed,including the topological design process of the PM,and the main topological characteristics such as the degree-of-freedom and coupling degree κ.Secondly,according to the kinematic modeling method based on topological characteristics,the forward and inverse solutions of symbolic positions were found,from which the working space calculation of the PM was carried out based on the forward solution.At the same time,the position inverse equation was derived to obtain the Jacobian matrix of the PM,from which the velocity,acceleration and singularity of the PM were derived.Thirdly,the sequential single-chain method based on the principle of virtual work was used to carry out reverse dynamic modeling,and the driving force change curve of the actuated pair of the PM was obtained,the supporting reaction force of the kinematic pair at the sub-kinematic chain(SKC) connection were also obtained,which were then verified by ADAMS dynamic simulation.Finally,the potential application scenarios of this mechanism used as automatic material transfer and unloading device between conveyor belts with different heights were conceptually designed and analyzed.The research result can provide a theoretical basis for the efficient kinematics,dynamic modeling and analysis,performance optimization and prototype development of the two-branch parallel mechanism with larger rotation space and partial motion decoupling.
作者
沈惠平
朱晨阳
李菊
李涛
SHEN Huiping;ZHU Chenyang;LI Ju;LI Tao(Research Center of Advanced Mechanism,Changzhou University,Changzhou 213016,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2023年第2期419-429,440,共12页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(51975062)。
关键词
并联机构
拓扑设计
拓扑特征
运动学
动力学
虚功原理
parallel mechanism
topological design
topological features
kinematics
dynamics
virtual work principle
