剪式机构的刚柔耦合动力学建模与仿真

摘要

为了获得剪式机构在展开和折叠过程中的动力学特性,减轻机构工作过程中的耦合振动,通过模态分析,得到了剪式机构的固有频率,采用自然坐标建立了剪式机构的刚柔耦合动力学模型,建模方法易于程式化且适合通过计算机编程实现。在Mathematica环境下编程进行数值求解和仿真,得到剪式机构末端的动力学响应曲线及耦合振动引起的位置误差,证明剪式机构在展开和折叠过程中存在高频弹性振动,不能忽略振动引起的惯性力对机构运动的影响。在此基础上,分析并仿真了结构参数对耦合振动的影响,有利于剪式机构的优化设计和控制。%In order to obtain the dynamic performance of scissor structure and restrain the coupled vibration,the natural frequencies of scissor structure are obtained through modal analysis and the rigid and flexible coupling dynamic model is established in natural coordinates.The modeling method is formulaic and liable to be realized with computer program.The dynamic response curve and the position error due to elastic vibration of the flexible scissor structure are given through numerical simulation of Mathematica.The simulation results indicate the existence of high-frequency elastic vibration during the expanding and folding of scissor structure.Because the inertial force caused by elastic vibration cannot be ignored,the influences of structural parameters on the coupled vibration are studied.The conclusions will benefit the optimization and control of flexible scissor structure.