【摘要】 为了快速高效地建立空间机构运动模型以进行运动学特性分析,运用多体动力学原理,提出了一种计算机符号建模与数值的计算方法.在每根杆件上的运动副处建立笛卡尔直角坐标系,用这些坐标系之间的关联关系来描述空间机构的结构形态,推导了同一杆件上2个坐标系之间的变换关系,得到了杆件形状矩阵.根据运动副的类型和属性,推导了同一运动副处不同杆件上2个坐标系之间的变换关系,得到了运动副约束矩阵.通过在运动链上连续使用变换矩阵,建立了空间机构的数学模型,并用推导的运动方程对时间求导,得到了空间机构的速度和加速度方程.研究表明,由开发的空间机构运动学分析软件,结合空间4杆机构的运动学分析,验证了建模与求解方法的正确性,从而为空间运动机构建模与运动学分析提供了一种有效的方法.更多还原

【Abstract】 To rapidly and efficiently model and analyze the kinematics characteristics of spatial mechanism kinematics,a computer symbols model and a computational method were proposed based on multi-body dynamics theory.The relationship among the Cartesian coordinates which are built on the joints of each link was utilized to describe the configuration of spatial mechanisms.The link shape matrices were obtained from the relationship between the two coordinate systems on the same link.According to the type and property of joints,the joint constrain matrices were obtained from the relationship between the two coordinate systems of the same joint on the two links.Using these transform matrices on the kinematics chains in series,the mathematical model of spatial mechanisms was developed,and the motion equations of spatial mechanisms were derived.The velocity equations and acceleration equations were obtained by the time first derivatives and second derivatives of the motion equations.Accordingly,a general software was developed for analyzing spatial mechanism kinematics.A spatial four bars mechanism was modeled and analyzed by this software,and the correctness of the proposed method and the software were verified.更多还原