新型大行程柔顺并联机构理论与实验研究

发布时间：2018-04-06 22:02

本文选题：柔顺虎克铰　切入点：柔顺并联机构　出处：《华南理工大学》2014年博士论文

【摘要】：随着军事工程、光通信工程、生物工程、精密机械工程、精密光学工程等领域的科学技术不断发展，迫切需要各方面性能都更加出色的新型机构来适应越来越高的操作需求。合理构型的柔顺并联机构操作精度、响应速度、承载力、可控性、灵活性等方面都有比较出色的表现，但运动范围普遍较小，柔顺铰链的类型、材料的刚度和材料的弹性极限严格的限制了转动角度的大小。本文对大行程柔顺虎克铰设计及大行程柔顺并联机构设计问题作了以下研究：（1）设计了一种新型多簧片大变形柔顺虎克铰，通过伪刚体模型计算和非线性有限元仿真，验证了该铰链结构的合理性和模型的有效性，该设计基本符合虎克铰的转动特性。在虎克铰的初步设计基础上，又针对虎克铰的各项性能进行了多目标优化设计，增加运动行程、提高非功能方向的刚度、提高承载力、便于加工等，，得到装配式柔顺虎克铰为最优结构。该柔顺虎克铰可实现高精度、大角度的二维转动运动，采用直线与曲线复合簧片对称分布柔度设计，提高了铰链的轴向刚度和径向刚度，当受到纯转矩作用时，基本没有轴心漂移，是一种性能优良的大行程柔顺虎克铰。（2）基于大变形柔性虎克铰设计了PUU运动链，将4条PUU运动链对称布置，构造了一种空间三自由度大行程柔顺并联机构。使用螺旋理论对PUU运动链和并联机构的自由度进行了分析，建立了三自由度柔顺并联机构的等效伪刚体模型，推导了机构的位置反解方程和速度雅克比矩阵，并利用非线性有限元软件进行了模拟仿真，结果表明机构的等效伪刚体模型是有效的。这种三自由度柔顺并联机构可达立方厘米级的工作空间。（3）基于大变形柔性虎克铰设计了PURU运动链和UC运动链，并使用4条PURU运动链和1条UC运动链，构造了一种空间四自由度大行程柔顺并联机构。使用螺旋理论对PURU运动链、UC运动链和并联机构的自由度进行了分析，建立了四自由度柔顺机构的等效伪刚体模型，推导了机构的位置反解和速度雅克比矩阵，根据柔性虎克铰的转角范围，分析了四自由度柔顺机构的工作空间。根据非线性有限元软件的比较结果，该柔顺机构可以输出高精度大位移的三维转动和一维平动。 (4)根据前述章节的分析结果，对大行程三自由度和四自由度柔顺并联机构的输出行程做了实验研究。根据实验结果，对相对误差进行了讨论，并根据误差来源对柔顺机构的等效伪刚体模型进行修正。使用修正公式进行的实验结果表明，修正公式是有效的，显著减小了相对误差。
[Abstract]:With the continuous development of science and technology in the fields of military engineering , optical communication engineering , biological engineering , precision machinery engineering , precision optical engineering and so on , new mechanisms with better performance are urgently needed to adapt to the increasing operation demand . The reasonable configuration of the flexible parallel mechanism has excellent performance in operation precision , response speed , bearing capacity , controllability , flexibility and the like , but the range of motion is generally small , the type of the flexible hinge , the rigidity of the material and the elastic limit of the material strictly limit the size of the rotation angle .

In this paper , the design of a large - stroke flexible joint and the design of a large - stroke flexible parallel mechanism are studied in this paper .

( 1 ) The design of a novel multi - reed large deformation flexible hooker hinge , which is based on the pseudo - rigid body model and the nonlinear finite element simulation , verifies the rationality of the hinge structure and the validity of the model . The design basically accords with the rotation characteristic of the Hooke ' s hinge .

( 2 ) The PUU kinematic chain is designed based on the large deformation flexible Hooke hinge . Four PUU kinematic chains are symmetrically arranged , and a three - degree - of - freedom large - stroke compliant parallel mechanism is constructed . The equivalent pseudo - rigid body model of the three - degree - of - freedom flexible parallel mechanism is established by using the spiral theory , and the simulation simulation is carried out by using the nonlinear finite element software , and the result shows that the equivalent pseudo - rigid body model of the mechanism is effective .

( 3 ) The puru kinematic chain and the UC kinematic chain are designed on the basis of the large deformation flexible Hooke hinge , and four PURU kinematic chains and one UC kinematic chain are used to analyze the degrees of freedom of the four - degree - of - freedom flexible mechanism by using the spiral theory , and the working space of the four - degree - of - freedom compliance mechanism is deduced . According to the comparison result of the nonlinear finite element software , the compliant mechanism can output three - dimensional rotation and one - dimensional translation of high - precision large displacement .

( 4 ) According to the analysis result of the previous chapter , the output stroke of the three - degree - of - freedom and four - degree - of - freedom flexible parallel mechanism is experimentally studied . Based on the experimental results , the relative error is discussed , and the equivalent pseudo - rigid body model of the compliant mechanism is corrected according to the error source . The experimental results show that the modified formula is effective and the relative error is significantly reduced .

【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TH112

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