模块化可重构少自由度并串结构及其基本理论研究

发布时间：2018-05-16 01:30

本文选题：模块化 + 可重构　；参考：《青岛科技大学》2017年硕士论文

【摘要】：少自由度并串结构汲取了并联和串联两种机构的优势,不仅具有较大的工作空间,而且机构刚度大、承载能力强。但是不同构型的并串结构一般只能完成特定的工作任务,当工作任务发生改变的时候,就要更换成相应类型的结构。为了解决这一难题,本文从模块化的角度出发,分析了常见少自由并串结构的基本特征并对其进行了分类和模块化设计,进而提出了一种新型模块化可重构少自由度并串结构,并从静力学和动力学两方面对它进行了研究。首先,基于并联机构常用的综合及分类方法,将常见的少自由度并联机构分成四类,并对每一类型的结构进行了详细地分析,提取其特征。将组成并联机构的运动副分为基本运动副和和复合运动副两大类,并分析了五种对模块化结构设计非常有用的复合运动副。分析了一系列具有确定运动特性的运动支链类型,包括简单运动副支链类型、复合运动副支链类型以及具有确定运动特性的2-5自由度运动支链,为模块化可重构并联机构的研究奠定了基础。其次,基于对常见少自由度并联机构结构特征的分析,设计出固定平台模块、运动平台模块、运动副模块、连接器模块以及连杆模块。通过运动副模块、连接器模块和连杆模块构造了一系列二至五自由度的运动支链。根据并联机构综合理论,利用不同的模块造出一系列模块化并联机构。然后,提出一种新型模块化可重构少自由度并串结构,并对它的结构特征进行了详细地分析。运用螺旋理论和修正的Kutzbach Grüble公式对该结构的自由度进行计算,得出它的自由度数为6。基于机构影响系数法对该结构的速度和加速度进行理论推导,得到它速度和加速度的数学模型。最后,运用三维制图软件Creo创建出虚拟样机模型,利用数据接口将模型导入到工程分析软件ANSYS和ADAMS中。通过对虚拟样机模型进行静力学和运动学仿真,得到它的静力学图像以及工作平台在不同参数设置下的速度、加速度变化曲线和位置变化图,从而验证了速度和加速度数学模型的正确性。本文所做的工作,为模块化理念在少自由度并串结构领域的运用打下了坚实的基础,对建立一套适用于模块化可重构少自由度并串结构的系统理论具有重要意义。
[Abstract]:The low degree of freedom parallel structure absorbs the advantages of parallel mechanism and series mechanism. It not only has a large workspace but also has a large stiffness and a strong bearing capacity. However, the conjunctive structure of different configurations can only accomplish a specific task. When the task changes, it will be replaced by a corresponding type of structure. In order to solve this problem, this paper analyzes the basic characteristics of common few free parallel string structures from the angle of modularization, classifies them and designs them in modularization, and then proposes a new modular reconfigurable low degree of freedom parallel string structure. It is studied from static and dynamic aspects. Firstly, based on the common synthesis and classification methods of parallel mechanisms, the common parallel mechanisms with less degrees of freedom are divided into four categories, and each type of structure is analyzed in detail to extract its features. The kinematic pairs composed of parallel mechanism are divided into two categories: basic kinematic pair and composite kinematic pair. Five kinds of composite kinematic pairs which are very useful for modular structural design are analyzed. A series of kinematic branching chains with certain kinematic characteristics are analyzed, including simple kinematic pair branching chains, composite kinematic pair branching chains and 2-5-DOF kinematic branching chains with certain kinematic characteristics. It lays a foundation for the research of modular reconfigurable parallel mechanism. Secondly, based on the analysis of the structure characteristics of the common parallel mechanism with less degrees of freedom, the fixed platform module, the motion pair module, the connector module and the connecting rod module are designed. A series of two to five degrees of freedom motion chains are constructed by motion pair module, connector module and connecting rod module. According to the synthetic theory of parallel mechanism, a series of modular parallel mechanisms are built by using different modules. Then, a new modular reconfigurable parallel-string structure with less degrees of freedom is proposed, and its structural characteristics are analyzed in detail. The degree of freedom of the structure is calculated by using the helical theory and the modified Kutzbach Gr 眉 ble formula, and its number of degrees of freedom is 6. The velocity and acceleration of the structure are derived theoretically based on the mechanism influence coefficient method, and the mathematical model of the velocity and acceleration is obtained. Finally, the virtual prototype model is created by using the 3D drawing software Creo, and the model is imported into the engineering analysis software ANSYS and ADAMS by the data interface. Through statics and kinematics simulation of the virtual prototype model, the static image and the velocity, acceleration curve and position change diagram of the work platform under different parameters are obtained. Thus the correctness of the mathematical model of velocity and acceleration is verified. The work done in this paper lays a solid foundation for the application of modularization concept in the field of low degree of freedom parallel string structure, and is of great significance to the establishment of a set of system theory suitable for modular reconfigurable low degree of freedom parallel string structure.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH112

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