一种长钢轨扣件回收装置的运动学分析与仿真

针对一种新型长钢轨扣件回收装置进行运动学分析和仿真研究。根据扣件回收的作业要求,确定了收料机构运动特征;利用解析法建立了运动学逆解模型,并对该收料机构进行了尺度参数设计,通过对逆运动学模型进行数值求解,获得主动件的运动规律。应用ADAMS软件建立仿真模型,验证了运动学模型的正确性。为该机构的优化设计和动力学分析提供了参考。     

基于Matlab的偏置曲柄滑块机构的运动特性仿真研究

介绍了Matlab在偏置曲柄滑块机构运动学分析中的应用,根据矢量法建立机构的运动学方程,采用Matlab／Simulink对其进行运动学仿真及运动分析,得到偏置曲柄滑块机构的运动曲线。该方法求解效率高,在机构运动特性分析中具有一定的应用价值。     

基于Matlab的偏置曲柄滑块机构的运动特性仿真研究

介绍了Matlab在偏置曲柄滑块机构运动学分析中的应用,根据矢量法建立机构的运动学方程,采用Matlab/Simulink对其进行运动学仿真及运动分析,得到偏置曲柄滑块机构的运动曲线.该方法求解效率高,在机构运动特性分析中具有一定的应用价值.     

基于MATLAB/Simulink的内涨式夹紧机构运动学仿真

通过对热煨弯管坡口机内涨式夹紧机构进行分析,将其简化为双滑块机构,通过机构运动学方程建立了仿真模型,利用Matlab/Simulink软件对机构进行了运动学仿真分析,得到了机构的各种运动参数仿真结果,验证了仿真的正确性和有效性。     

数控弯管机机构运动学建模与加工过程仿真技术

针对现有数控弯管加工过程仿真方法通用性差的问题,提出一种基于机构运动学模型的数控弯管加工过程仿真方法。在运用多体系统运动学理论对数控弯管机进行机构运动学分析的基础上,建立了描述数控弯管机运动特征和结构参数的信息模型及机构运动学模型,采用Newton-Raphson迭代法对数控弯管机机构运动学方程进行求解,给出了数控弯管机运动和导管动态成形的运动规划算法,实现了任意结构单头数控弯管机的加工过程仿真。最后开发了原型系统,以SWING和VB200HP两种数控弯管机为例对所提方法进行了验证。     

基于SIMULINK的Zero-Max型无级变速器运动学仿真

利用SIMULINK仿真工具,对Zero-Max型脉动式无级变速器机构运动学仿真的方法与过程进行了研究.在建立其运动学数学模型基础上,根据SIMULINK的特点构建了运动学仿真模型,通过实时仿真得到了无级变速器中各杆件的位置、速度与加速度变化规律曲线,并进一步对其运动特性进行了分析研究.实例仿真结果表明,该方法简便、直观、可靠、通用性好,适用于复杂机构的运动学仿真.     

人体骨盆位姿模拟机构的运动学分析及仿真

根据人体骨盆的运动规律,设计了一种4自由度人体骨盆位姿模拟机构.建立了人体骨盆位姿模拟机构的正运动学模型和逆运动学模型,并推导出了机构的雅可比矩阵.基于机构的运动学模型建立了仿真模型,并采用MATLAB/Simulink对人体骨盆位姿模拟机构进行了仿真分析.仿真结果表明:该机构方案是可行的,能够模拟人体骨盆的运动规律.同时仿真结果也验证了运动学模型的正确性.     

Stewart平台运动学仿真分析

Stewart平台的运动学分析是确定系统结构参数、设计液压动力机构、确定系统流量、选择伺服阀的基础和前提。根据Stewart平台机构学原理,在ADAMS/View模块下建立了系统的虚拟样机模型,并对其添加约束和驱动后进行了运动学仿真,得到了各作动器运动参数在不同运动姿态时的变化规律。该方法避免了大量的数学计算与计算机编程工作,通过CAE方法实现了对Stewart平台的运动学仿真。     

乳化液泵曲柄滑块机构的运动仿真与有限元分析

以BRK500/37.5型乳化液泵曲柄滑块机构为研究对象,对曲柄滑块机构进行运动学分析,求解滑块的运动学方程。并利用UG软件的运动仿真模块对曲柄滑块机构作运动仿真分析,得出滑块在工作时的位移、速度和加速度仿真曲线图。最后利用ANSYS Workbench软件对滑块进行有限元分析,得出滑块在最大工作压力下的应力应变值,为曲柄滑块机构的改进奠定了理论基础。     

一种新型的多足仿生机器人的机构设计与研究

提出一种新型的多足仿生机器人的运动机构,该机构具有运动灵活,自由度少的特点.利用D-H矩阵对该机构基本运动单元的运动学进行了理论分析,给出了运动学方程.基于虚拟样机技术对该运动学方程进行了仿真验证,结果表明运动学方程是正确的.建立了这种新型的多足仿生机器人的虚拟样机,并对其进行了虚拟样机的仿真研究.制作出了简易的一对足的实物试验机构.     

Hierarchical clustering approach for determination of isomorphism among planar kinematic chains and their derived mechanisms

The problem of isomorphism among kinematic chains and their derived mechanism has been a hot area of research from last several years. The researchers so far have proposed many methods which are mainly based on characteristic polynomial and some code based methods to test the isomorphism among kinematic chains. In this present communication a hierarchical clustering based computerized method is proposed for the above said problem and it is tested for planar kinematic chains upto twelve links without any counter examples. In this method a hierarchical clustering algorithm is also developed for the identification of distinct mechanism derived from kinematic chains. In this method kinematic chains are represented in the form of weighted squared shortest path distance matrix and this matrix is further transformed in the form of tree or dendrogram with the help of hierarchical clustering algorithm. This algorithm directly gives the number of distinct mechanism derived from a given kinematic chain. The cophenetic correlation coefficient of dendrogram is used as an index for isomorphism identification among kinematic chains. The proposed method is efficient and accurate and only one matrix for a given kinematic chain is developed for the determination of distinct mechanisms. This method is successfully examined for one degree of freedom, 6, 8, 10, 12 links planar kinematic chains, 9 links two degree of freedom and 10 links three degree of freedom planar kinematic chains. The computer algorithm for the proposed method has been proposed which can easily be converted into a computer program. These results are useful for designers to detect isomorphism in mechanisms derived from kinematic chains and duplication among kinematic chains.     

基于Matlab和VC++的凸轮机构中从动件运动规律参数化设计

采用 Matlab和 VC++6 .0联合编程的方法 ,在 VC++6 .0环境下 ,调用 Matlab的 C++函数库 ,开发凸轮机构运动规律参数化设计软件模块系统。本文把从动件的复合运动规律分为常用和非常用两种 ;对于常用的复合运动规律可以对其烦琐的数学表达式直接计算求解 ,而对于有特殊要求的非常用复合运动规律是由基本的运动规律按照拼接条件复合而成。该软件模块为凸轮机构 CAD/ CAM技术及其他类型间歇机构的 CAD软件开发奠定了基础     

Applications of equivalent components concept on the singularity analysis of TRR–XY hybrid parallel kinematic machine tools

The design of using a parallel kinematic mechanism as a structure of machine tools has several good points compared with the traditional machine tools. However, the problem of singularity is usually encountered during real applications. Therefore, singularity analysis is very essential for using a parallel kinematic mechanism in real machining applications. Screw theory based on the Plücker coordinate system is one of the effective methods for analyzing the singularity of a parallel kinematic mechanism. A TRR–XY five DOF parallel kinematic machine tool that was developed in this research is adopted as an example for investigating the feasibility of this method. A 6×6 matrix calculation is usually required in screw theory for analyzing a six DOF mechanism. For a three DOF mechanism, the analysis using the screw theory becomes more complicated. An equivalent component method is addressed in this research to simplify the singularity analysis for a three DOF mechanism. The effects of differently designed dimensions of machine tools on the singularity are also investigated in this research.     

行星齿轮变速机构运动学分析

用图论的方法对行星齿轮变速机构进行运动学分析。将基本行星轮系表示成三角形单元的形式,每个行星单元满足相应的运动方程。首先建立行星变速机构初始图论模型,根据控制元件结合情况,得到各个挡位的图论模型,再由相应的运动方程求解各个挡位传动比。以三自由度、两行星排行星变速机构和二自由度、四行星排行星变速机构为例,给出了系统的分析过程。该方法具有简单、规范、通用性较强、易于编程的特点,可适用于多自由度行星齿轮变速机构的分析。     

Creative design of a wheel damping mechanism

The objective of this work is to provide a systematic method for the creation of all possible wheel damping mechanisms based on a parent mechanism. The original mechanism is generalized into a linkage type kinematic chain according to the rules defined. The self-assortment and the related assortments of this kinematic chain are derived by using the technqiue of number synthesis. These derived kinematic chains are respecialized, by applying the generalized rules backward based on some design constraints, to create a total of 98 new wheel damping mechanisms.     

采用间接测量法对平面3-RPR机构进行运动学标定的仿真

采用间接测量对平面机构进行标定时，需要引进标准测量参照物，但参照物本身仍可能存在一定的尺寸误差；另外间接测量时要不断变换标准测量参照物的位置，又会引进位置误差。为便于解决实际问题，使研究更具可操作性，将上述误差和待标定的机构结构误差一起考虑对机构进行了标定仿真，同时在仿真过程中采用矩阵重构的方法来解决测量误差扰动的问题，避免了大规模的空间寻优。仿真结果表明，可以通过让动平台走过不同的轨迹组合来实现对平面机构的标定。     

Optimal design of a six-axis vibration isolator via Stewart platform by using homogeneous Jacobian matrix formulation based on dual quaternions

A six-axis vibration isolation system is essential to high-precision space systems for attenuating vibrations on precise instruments. The kinematic optimal design is researched for the space six-axis vibration isolator via Stewart mechanism. Jacobian matrix is the basis of the kinematic performance index. However, the conventional Jacobian matrix is not usually dimensionally homogeneous due to the inhomogeneous physical units, caused by the different mathematical representations of the rotation and translation. In this paper, we propose a dual quaternion approach to derive the dimensionally homogeneous Jacobian matrix of a general six-axis parallel mechanism. Two quaternions are used to parameterize the rotation and translation of the platform. The dimensionally scaling factor for the generalized Jacobian matrix is defined as the ratio of the norms of the two quaternions. The dimensionally homogenous Jacobian matrix is then obtained and applied to the optimal design of the six-axis vibration isolator. The performance index of isotropy is considered to make the isolator minimum kinematic coupling in its working configuration.     

平面闭式运动链简图自动绘制的最大环路法

机构运动链结构简图的自动绘制,直接关系到机构设计的效率与可靠性。在对平面闭式机构运动链的拓扑特性研究基础上,基于缩杆邻接矩阵,提出一种运动链结构简图自动绘制的最大环路方法。此方法采用广度优先生成树算法获得运动链的独立回路,并通过独立回路的加减运算得到最大可行外环。根据回路关系逐步修正最大可行外环,使各独立回路成为其非交叉规范化内环。在运动链结构简图绘制过程中,根据外环和内环情况,将运动链中的运动副布置在由外往内的同心圆内接正多边形的顶点上,使绘制的运动链简图规范、美观。在对这种基于外环与内环关系的简图自动绘制算法研究过程中,借助多个机构实例进行说明。研究与应用结果表明,最大环路法具有实现简单、方法完备的特点,适用于多杆多自由度平面闭式运动链结构简图的自动绘制,应用于机构设计中,可极大地提高设计效率。     

基于图谱法的新型运动分岔并联机构型综合

多模式并联机构在航空航天、机械加工、医疗康复等领域均极具应用前景,但目前能够实现多模式的运动分岔并联机构类型较少,绝大多数运动分岔并联机构中含有变自由度性质的RER支链,为此基于图谱法综合了一类新型运动分岔并联机构且机构中含有4类变自由度性质支链与已有的RER支链不同。首先基于图谱法以机构初始位置两瞬时转动自由度线非共面且相互垂直为例对2T1R运动分岔并联机构进行综合,随后将机构含有的URR支链中和定平台相连接的R副轴线方向改变,使其具有2R2T和3R1T两种自由度性质。将改进后的URR支链配置方案应用到部分4自由度和5自由度支链中,提出另外三类变自由度支链,每种类别支链分别有4、12、32种。以机构中含有4类不同变自由度性质的支链为分类依据,综合出四大类同时具有2T1R+2R1T两模式新型运动分岔并联机构,共包括12种子类别;以第4类变自由度支链为例,将其引入到并联机构中,通过图谱法综合出具有3T1R+2R2T两模式新型运动分岔并联机构。     

Higher-order continuation method for the rigid-body kinematic design of compliant mechanisms

Compliant mechanisms are of great interest in precision engineering. In this paper, we propose a higher-order continuation method to help their rigid-body kinematic design. The method helps to investigate the choice of a mechanism configuration through the whole exploration of the workspace, and eases the kinematic analysis to avoid, or take advantage of, the vicinity of kinematic singularities. Such approach is relevant for planar and quasi-planar mechanisms that can be obtained with micro-manufacturing processes adapted to precision applications. The higher-order continuation method allows for a direct and accurate plotting of the input–output relationship of any mechanism by considering only its geometrical closed-loop equations, i.e. without the complex derivation of any analytical model. We show that these plots, called bifurcation diagrams, reveal essential information such as the joint velocity profile and the presence of singular configurations. Moreover, the continuous and accurate computation of the mechanism configuration in the vicinity of singularities provides detailed information about the kinematic behavior of the mechanism in its extreme positions. For the design of compliant mechanisms, the designer can advantageously use the bifurcation diagrams to evaluate the relevance of the selected mechanism, then to identify a configuration in order to obtain desired kinematic properties without the derivation of the inverse kinematic model (IKM) or the direct kinematic model (DKM). The method is exemplified with a 3 universal-joint and 3 spherical-joint mechanism (3-US), the IKM and DKM of which cannot be derived analytically. The latter has a large workspace and special kinematic behaviors consisting of a screw-like motion and a platform gyration, which have not been studied before and could lead to novel compliant devices.