【作者】 曲云霞；

【导师】 范顺成；

【作者基本信息】 河北工业大学 ， 机械设计及理论， 2009， 博士

【摘要】 解耦球面并联机构是一类具有工程实际应用价值的并联机构,研究和开发该类机构,并对其性能进行全面的分析是机械系统创新及应用的基础性和关键性工作之一。本文以二自由度解耦球面并联机构的分析与开发为目标,运用机构学理论以及计算机仿真技术等,较系统地进行了机构构型研究、运动学分析、机构结构尺寸与机构性能的关系和误差分析等机构设计的关键技术问题,取得了如下创新性成果:1.给出了二自由度RR &Π和LRRR&PRR解耦球面并联机构的一般构型,并针对RR&PRR机构,从工作空间出发,结合结构设计及运动设计,提出了该机构的两种改进构型;2.针对二自由度RR &Π和LRRR&PRR解耦球面并联机构,完成了运动学分析,分别建立了两种解耦球面并联机构的运动学方程,给出了机构的位置、速度和加速度正、反解的表达式;3.针对两种机构构型,完成了机构运动工作空间和奇异位形分析,并给出了两种机构的实际工作空间范围;4.应用机构设计的无量纲法,建立了机构的空间模型;给出了机构的速度性能指标、承载能力性能指标和刚度性能指标的描述方法,并提出了应用性能指标的均值及其波动情况描述机构性能的新方法,以等值线的形式分别绘制了机构的性能图谱;研究了机构尺寸参数与机构性能之间的关系,给出了机构尺寸参数与机构性能间的定量关系,确定了在不同性能指标要求下机构杆件无量纲设计尺寸的取值范围;5.应用环路增量法,给出了机构的闭环方程,建立了机构各杆件原始参数误差间的约束关系,并通过机构的位姿误差模型、速度误差模型以及加速度误差模型,分析了机构动平台运动误差与机构杆件参数误差的关系。论文工作为丰富并联机构构型设计理论体系、促进球面并联机构的工程应用奠定了坚实的基础。更多还原

【Abstract】 Decoupled spherical parallel mechanisms are a type of useful and applicable parallel mechanisms in engineering. In-depth investigation and comprehensive analysis to this type of mechanisms is the foundational key work for innovation and utilization of mechanical sysytems.Aimed at analysing and developing 2-DOF decoupled spherical parallel mechanisms, this dissertation systematically deals with key issues of the mechanisms design, such as mechanism configuration, kinematics analysis, relations between linkage length and mechanism performances, and movement error analysis, etc., by employing mechanism theory and computer simulation techniques. The creative contributions may be summarized as follows.1. The general configurations of two types of 2-DOF decoupled spherical parallel mechanisms, termed respectively as RR &ΠLRand , are given. For the mechanism, in order to meet the workspace requirements, two types of improved mechanism are presented by combining structure design and kinematics design.2. Aimed at the mechanisms of RR &ΠLRand , kinematics analyses are conducted and the kinematics equations are also established, thus deriving and formulating the direct and reverse solutions of position, velocity and acceleration.3. The workspace and singular configuration of those two mechanisms are analyzed, and their practical workspaces are also given.4. The spatial models of the mechanisms are established by employing the non-dimensional method to design mechanisms. The methods of describing the performance indexes of velocity, load-carrying capacity and stiffness are given. Also, a novel method to describe the mechanism’s performances by using the mean value of performance indexes and its fluctuation is proposed. And the performance spectrum diagrams are drawn in the form of contour series. In addition, the effect of linkage length on mechanism performance is also studied, and the relations between linkage length parameters and the mechanism performance are therefore quantitatively given. And the effective ranges of the non-dimensionally designed linkage length are determined under different requirements for performance indexes.5. The closed-loop equations of the mechanisms are given by employing closed-loop increment method. After establishing the constraints relations among the original linkage parameters errors, the relations between the movement error of the moving platform and the linkage length are analyzed by using the position and pose error models, velocity error models and acceleration error models.The work in this dissertation will lay a solid foundation for developing the configuration design theory of parallel mechanism and for boosting application of spherical parallel mechanism in engineering.更多还原