基于分形理论的混联机器人机构设计方法的研究

发布时间：2018-04-23 16:21

本文选题：混联机器人 + 分形理论　；参考：《江南大学》2017年硕士论文

【摘要】：混联机构由于其兼具串联机构工作空间大、易与控制和并联机构结构稳定、刚性好、累积误差小、动态性能好、精度高的优点,并能避免单纯串、并联机构所带来的问题,并且能很好的应用于工业制造中,从而备受国内外学者和研究院的关注,占据了机构学领域的重要一角。但目前针对具有多路径横向非典型性混联机构的构型设计及型综合方法的研究尚在发展中阶段。因此,基于分形理论和机构拓扑图,本论文提出一种全面、系统的混联机器人构型综合理论和设计方法。首先,介绍了空间多环拓扑结构设计的理论基础,并通过工作场合的特点,给出了开环拓扑结构和闭环拓扑结构两种类型。其中,前者的输出动平台数目大于一,适合多点协同工作环境;后者的输出平台有且仅有一个,应用于大多数场合下。并且,提出了将分形理论应用于空间多环拓扑结构的方法,通过链分形、平台分形和链台分形三种分形方式,快速有效的生成了不同机构拓扑图。其次,分析了混联机构的运动特征,主要由运动副、支链和路径组成。其逻辑顺序为:机构由路径并联而成,路径由支链串联而成,支链由运动副通过不同组合方式组建而成。在此基础上,提出了8位二进制码的表达方式。同时,在混联机构的逻辑运算中,提出了路径法则,解决了运算过程中路径这一新添加的元素所带来的问题。并基于位移子集的概念,针对串联与并联运动的拓扑关系,建立了串并联运算法则,解决了各运动特征的输出位移子集的计算问题。然后,提出了具体的基于分形理论的混联机构的设计方法。在机构拓扑图的基础上,适配运动副,并对该布局进行审核,确定其满足设计条件。在此基础上,提出了系统的混联机构型综合流程,并将此型综合理论应用于少自由度混联机构的型综合,实现了三自由度、四自由度和五自由度这三种混联机构的型综合,并运用末端运动特征分析方法逐一验证了上述机构。最后,针对踝关节损伤的治疗设备问题,提出了一种五自由度混联式踝关节康复机构。其由一个两转动一移动(2R1T)机构串联一个两移动(2T)机构,实现了踝关节的背屈、跖屈、内翻、外翻的两个转动和空间内三维移动,即该机构为三移动两转动混联机构。设计了两套2R1T机构构型,通过ADAMS建模和仿真,实现对该机构的运动学分析,验证了机构的运动输出,并确定混联式踝关节康复机构的整体构型。从中可发现机构运动平稳合理,为进一步机构的实体化提供了可靠的保证。
[Abstract]:The hybrid mechanism has the advantages of large workspace of series mechanism, stable structure of control and parallel mechanism, good rigidity, small cumulative error, good dynamic performance and high precision, and can avoid the problems caused by simple series-parallel mechanism. And it can be well applied in industrial manufacturing, which has attracted the attention of domestic and foreign scholars and research institutes, and occupies an important part in the field of mechanism science. However, the research on configuration design and synthesis method of multipath transversal heterodyne mechanism is still in the developing stage. Therefore, based on fractal theory and mechanism topology, this paper presents a comprehensive and systematic synthesis theory and design method of hybrid robot configuration. Firstly, the theoretical basis of space multi-ring topology design is introduced, and two types of open loop topology and closed loop topology are given through the characteristics of the working environment. Among them, the former has more than one output moving platform, which is suitable for multi-point cooperative working environment, and the latter has only one output platform, which is applied in most situations. Furthermore, a method of applying fractal theory to spatial multi-ring topology is proposed. Through three fractal methods, chain fractal, platform fractal and chain table fractal, different mechanism topology graphs are generated quickly and effectively. Secondly, the kinematic characteristics of the hybrid mechanism are analyzed, which are mainly composed of motion pair, branch chain and path. The logical sequence is as follows: the mechanism is parallel by the path, the path is connected by the branch chain, and the branch chain is formed by the kinematic pair through different combinations. On this basis, the expression of 8-bit binary code is proposed. At the same time, in the logic operation of the hybrid mechanism, a path rule is proposed, which solves the problem caused by the new added element of the path in the process of operation. Based on the concept of displacement subset, a series-parallel algorithm is established for the topological relation between series and parallel motion, which solves the problem of calculating the output displacement subset of each motion feature. Then, the design method of hybrid mechanism based on fractal theory is put forward. On the basis of the topology diagram of the mechanism, the kinematic pair is adapted, and the layout is checked to confirm that it meets the design conditions. On the basis of this, this paper puts forward the integrated flow of the system's hybrid on-line configuration, and applies this type synthesis theory to the type synthesis of the hybrid mechanism with less degrees of freedom, and realizes the type synthesis of the three kinds of hybrid mechanism, that is, three degrees of freedom, four degrees of freedom and five degrees of freedom. The mechanism is verified one by one by using the method of terminal motion feature analysis. Finally, aiming at the treatment equipment of ankle joint injury, a five degree of freedom hybrid ankle rehabilitation mechanism is proposed. It consists of a two-rotation, a moving-2R1T) mechanism in series with a two-moving-2T) mechanism, which realizes the two turns of the ankle joint such as dorsal flexion, metatarsal flexion, varus, valgus and three-dimensional movement in space, that is, the mechanism is a three-move, two-rotation hybrid mechanism. Two sets of 2R1T mechanism configurations are designed. Through ADAMS modeling and simulation, the kinematics analysis of the mechanism is realized, the kinematic output of the mechanism is verified, and the overall configuration of the hybrid ankle rehabilitation mechanism is determined. It can be found that the motion of the mechanism is stable and reasonable, which provides a reliable guarantee for the further materialization of the mechanism.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP242

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