基于少自由度并联机构的多维隔振研究

发布时间：2018-05-03 07:32

本文选题：少自由度并联机构 + 多维隔振　；参考：《山东大学》2014年硕士论文

【摘要】：随着人们对各种仪器设备的精密度、使用寿命及人体乘坐交通工具的舒适性的要求越来越高,如何有效地控制和预防多维振动引起的危害成为工程技术的一个重要问题。传统的多维隔振方法由于存在种种缺陷已不能满足多维振动控制要求,近年来,有学者将并联机构应用到多维隔振平台,并取得了一定突破,但由于实际应用中很多情况下并不需要完全实现六个自由度的隔振,而少自由度并联机构既能满足所需要的自由度数,又可以使机构简化,经济性好,控制相对容易,因此对相关理论进行研究十分必要。本论文是在国家自然科学基金“基于柔性变胞机构的精密设备多维振动的主动控制研究(51275275)”和山东省优秀中青年科学家科研奖励基金“基于柔性变胞机构的机载精密设备的振动主动控制研究(BS2010ZZ006)”的资助下,对少自由度并联机构的多维隔振进行理论与应用研究。本论文基于少自由度并联机构理论,设计综合了一种变自由度可重构并联机构,该机构具有两种构型,一种构型为3平移自由度并联机构,一种为3平移1转动自由度并联机构,这两种构型结构简单,机型紧凑,精度高,容易控制,而且结构相似,易相互转换,可作为搭建多维隔振平台的主体机构,实现三维和四维隔振。第一,将少自由度并联机构应用到多维隔振领域,首先对少自由度并联机构进行分析与综合,然后根据多维振动的特点来设计对应的少自由度并联机构,最后利用约束螺旋理论对机构的自由度进行验证分析。第二,对设计的少自由度并联机构进行了运动学和力学分析,对其位置正逆解、速度、解耦性、工作空间和力学方程进行了求解,分析证明这两种机构的运动学和力学方程比较简单,机构有很好的解耦性,适合作为隔振平台的主体机构使用。第三,分别以这两种少自由度并联机构作为多维隔振的主体机构,找出该机构的主动副的位置,并添加弹簧阻尼系统,构建多维隔振平台模型,建立动力学方程,分析了其固有频率及各结构参数变化对系统固有频率的影响。第四,利用动力学仿真软件Adams对该隔振平台进行运动学与动力学仿真,与Matlab软件分析计算的结果进行对比验证,证明了该机构具有良好的多维隔振效果。本文根据实际工程中多维振动的特点,将两种少自由度并联机构进行综合,设计出了一种可变自由度的可重构并联机构,并将其应用于机载设备的多维隔振,研究表明：两种并联机构分别能够实现三自由度和四自由度隔振,适于作为多维隔振的主体机构,并且具有优良的隔振性能。同时,两种机构结构相似,只需改变其中一个运动副便可实现机构间相互转换,也为下一步机构的变胞研究打下基础。
[Abstract]:With the increasing demands on the precision, service life and comfort of various instruments and equipments, how to effectively control and prevent the harm caused by multidimensional vibration has become an important problem in engineering technology. The traditional multi-dimensional vibration isolation method can not meet the requirements of multi-dimensional vibration control because of its various defects. In recent years, some scholars have applied parallel mechanism to multi-dimensional vibration isolation platform, and have made a certain breakthrough. However, in many practical applications, the vibration isolation of six degrees of freedom does not need to be fully realized, and the small degree of freedom parallel mechanism can not only satisfy the required number of degrees of freedom, but also simplify the mechanism, which is economical and relatively easy to control. Therefore, it is necessary to study the relevant theories. This thesis is based on the National Natural Science Foundation of China "active control of multi-dimensional vibration of precision equipment based on flexible metamorphic mechanism" and the "Research Award Fund for Young and Middle-aged scientists of Shandong Province" "Airborne based on flexible metamorphic Mechanism" Research on active Vibration Control of Precision equipment (BS2010ZZ006) ", The theory and application of multi-dimensional vibration isolation of parallel mechanisms with less degrees of freedom are studied. Based on the theory of small degree of freedom parallel mechanism, a variable degree of freedom reconfigurable parallel mechanism is designed and synthesized in this paper. The mechanism has two configurations, one of which is 3 translation degrees of freedom parallel mechanism. The two kinds of parallel mechanism are simple in structure, compact in type, high in precision, easy to control, similar in structure and easy to convert to each other, so they can be used as the main mechanism for setting up multi-dimensional vibration isolation platform. Three-dimensional and four-dimensional vibration isolation is realized. First, the small degree of freedom parallel mechanism is applied to the field of multi-dimensional vibration isolation. Firstly, the small degree of freedom parallel mechanism is analyzed and synthesized, and then the corresponding small degree of freedom parallel mechanism is designed according to the characteristics of multidimensional vibration. Finally, the degree of freedom of the mechanism is verified and analyzed by the theory of constrained helix. Secondly, the kinematics and mechanics of the designed parallel mechanism with less degrees of freedom are analyzed, and the forward and inverse solutions, velocity, decoupling, workspace and mechanical equations are solved. It is proved that the kinematics and mechanical equations of the two mechanisms are simple, and the mechanism has good decoupling, which is suitable for use as the main mechanism of vibration isolation platform. Thirdly, the two kinds of parallel mechanisms with small degrees of freedom are taken as the main mechanism of multi-dimensional vibration isolation, and the position of the active pair of the mechanism is found out, and the spring damping system is added to build the multi-dimensional vibration isolation platform model and establish the dynamic equation. The influence of the natural frequency and the structural parameters on the natural frequency of the system is analyzed. Fourthly, the kinematics and dynamics of the platform are simulated by the dynamic simulation software Adams, and the results are compared with the results of the Matlab software. The results show that the mechanism has a good multi-dimensional vibration isolation effect. According to the characteristics of multi-dimensional vibration in practical engineering, two kinds of parallel mechanisms with less degrees of freedom are synthesized, and a reconfigurable parallel mechanism with variable degrees of freedom is designed and applied to the multi-dimensional vibration isolation of airborne equipment. The results show that the two parallel mechanisms can achieve three and four degrees of freedom respectively and are suitable for multi-dimensional vibration isolation and have excellent isolation performance. At the same time, the structure of the two mechanisms is similar, only one of the two mechanisms can be changed by changing one of the motion pairs, which will lay the foundation for the next research on the mechanism transformation.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535.1

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