三构态变胞码垛机器人机构的非线性动力学研究

发布时间：2018-02-09 02:33

本文关键词： 码垛机器人变胞机构非线性动力学多尺度法优化设计　出处：《广西大学》2017年硕士论文　论文类型：学位论文

【摘要】：变胞机构作为机构学的新领域,受到了国内外学者的广泛关注,而且在生活和生产中已经得到广泛的应用。变胞机构的动力学特别是非线性动力学的研究,对于变胞机构的推广具有很大的实用价值,因此对变胞机构进行非线性动力学的研究十分必要。本文以一种三构态变胞码垛机器人机构为研究对象,首先用邻接矩阵法对机构进行了拓扑分析,描述了机构的构态变换过程,针对机构的变胞特点,设计了一种电磁变胞装置,通过分析机构系统的运动学,得到了机构系统的约束条件。而后以梁单元为基础,在考虑构件弹性变形以及冲击激励的情况下,应用有限单元法建立了系统的非线性动力学模型。然后利用振型坐标变换法对机构系统的非线性动力学方程进行了解耦变换,采用多尺度法对动力学模型进行求解,再采用Newmark法求出机构系统的稳态解,通过对机构在受冲击力激励作用下的共振机理分析,得到了机构系统产生共振现象的条件,并在此基础上分析了系统的主共振和超谐共振问题。之后利用Matlab软件对机构系统进行了数值仿真分析,讨论了机构系统在有负载和无负载两种情况下的动态响应。并在Adams中对机构系统进行了几何仿真分析,讨论了不同频率的冲击力激励所引起的非线性共振现象,通过碰撞点横向位移在Matlab和Adams中的时域图和频域图的对比,验证了机构系统的解析模型的可信性。最后利用遗传算法对机构系统各杆件的截面参数进行了动态优化设计,得到了各杆件截面参数的最优解,减轻了系统的总重量,提高了系统的稳定性,系统的动态性能得到了改善。
[Abstract]:As a new field of mechanism, metamorphic mechanism has been widely concerned by scholars at home and abroad, and has been widely used in life and production. The dynamics of metamorphic mechanism, especially nonlinear dynamics, has been studied. Therefore, it is necessary to study the nonlinear dynamics of metamorphic mechanism. Firstly, the topological analysis of the mechanism is carried out by using the adjacency matrix method, and the process of the structural transformation of the mechanism is described. According to the characteristics of the mechanism, an electromagnetic cell changing device is designed, and the kinematics of the mechanism system is analyzed. The constraint conditions of the mechanism system are obtained, and then on the basis of the beam element, the elastic deformation and shock excitation of the member are considered. The nonlinear dynamic model of the system is established by using the finite element method, and then the nonlinear dynamic equations of the mechanism system are decoupled by using the modal coordinate transformation method, and the dynamic model is solved by the multi-scale method. The steady-state solution of the mechanism system is obtained by using the Newmark method. By analyzing the resonance mechanism of the mechanism under the action of impact force, the conditions for the resonance phenomenon of the mechanism system are obtained. On this basis, the main resonance and ultra-harmonic resonance of the system are analyzed, and then the numerical simulation of the mechanism system is carried out by using Matlab software. In this paper, the dynamic response of the mechanism system with and without load is discussed. The geometric simulation analysis of the mechanism system is carried out in Adams, and the nonlinear resonance phenomenon caused by the shock force excitation at different frequencies is discussed. The credibility of the analytical model of the mechanism system is verified by comparing the time-domain and frequency-domain maps of the transverse displacement of the collision point in Matlab and Adams. Finally, the cross-section parameters of each member of the mechanism system are dynamically optimized by genetic algorithm. The optimal solution of the cross-section parameters of each member is obtained, the total weight of the system is reduced, the stability of the system is improved, and the dynamic performance of the system is improved.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP242

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