Numerical kinematic analysis of the standard macpherson motor-vehicle suspension system

In this paper, an efficient numerical algorithm for the kinematic analysis of the standard MacPherson suspension system is presented. The kinematic analysis of the suspension mechanism is carried out in terms of the rectangular Cartesian coordinates of some defined points in the links and at the kinematic joints. Geometric constraints that fix the distances between the points belonging to the same rigid link are introduced. The nonlinear constraint equations are solved by iterative numerical methods. The corresponding linear equations of the velocity and acceleration are solved to yield the velocities and accelerations of the unknown points. The velocities and accelerations of other points of interest as well as the angular velocity and acceleration of any link in the mechanism can be calculated.     

多刚体系统运动学分析的自然坐标法及在悬架运动学分析中的应用

本文介绍了一种适用于计算机分析的多刚体系统运动学分析的自然坐标法。利用自然坐标描述多刚体系统时,只需要一些点和一些单位向量,刚体的约束方程和运动副的约束方程组成了多刚体系统的运动学约束方程。约束方程均为线性或二次方程,因此求解方便。文中利用该方法分析了Maepherson悬架的轮胎横向滑移量、主倾内倾角等与车轮上、下跳动距离的关系。     

Dynamics of the macpherson strut motor-vehicle suspension system in point and joint coordinates

In this paper the dynamic analysis of the Macpherson strut motor-vehicle suspension system is presented. The equations of motion are formulated using a two-step transformation. Initially, the equations of motion are derived for a dynamically equivalent constrained system of particles that replaces the rigid bodies by applying Newton’s second law. The equations of motion are then transformed to a reduced set in terms of the relative joint variables. Use of both Cartesian and joint variables produces an efficient set of equations without loss of generality. For open chains, this process automatically eliminates all of the non-working constraint forces and leads to an efficient solution and integration of the equations of motion. For closed loops, suitable joints should be cut and few cut-joints constraint equations should be included for each closed chain. The chosen suspension includes open and closed loops with quarter-car model. The results of the simulation indicate the simplicity and generality of the dynamic formulation.     

Kinematic analysis of geared linkage mechanisms

A general approach to the kinematic analysis of planar geared linkage mechanisms (GLMs) is presented based on their structural topological characteristics. Firstly, a systematic method for decomposing a GLM into a series of sequential independent kinematic units, such as the simple links and the dyad link groups is proposed. The concept of tricolored graph and its mathematic expressions are introduced to describe the topological relationship between the kinematic pairs and the links in a GLM. The criteria and process for the structural decomposition and for choosing circuits using the theory of type transformation are established. Then the kinematic equations and the analytic solutions for the kinematic units are derived, and the method for the kinematic analysis of position, velocity and acceleration of GLMs is obtained in an algorithmic fashion. Finally, an application program has been developed, by which the whole work from the structural decomposition to the kinematic analysis can be accomplished automatically for any one of the GLMs. Some examples are used to illustrate the procedures.     

悬架与整车系统的性能协调分析方法研究

基于车辆系统动力学分析与最优化技术,提出了一种用于悬架与整车系统性能协调分析的新方法,能够以给定的整车性能要求为依据,确定与之相匹配的悬架特性参数。然后,通过算例验证了所提方法的有效性。     

空间弱撞击对接机构对接过程运动学分析

以空间弱撞击对接机构（LIDS ）对接过程为研究对象,通过运用Pro/ENGINEER软件建立机构的三维模型,采用矢量方法建立运动学模型,对其位置和姿态进行了分析。运用Newton -Raphson迭代法对空间弱撞击对接机构进行了位置正解分析,表明该方法可以迅速求解。以对接机构的三维模型和运动学模型为基础,通过MATLAB和ADAMS软件进行联合仿真分析,得到了满足设计要求的运动轨迹曲线,从而验证了运动学模型。对弱撞击对接机构进行了动力学仿真,得到了机构传力构件的最大受力情况。     

轮履复合机器人行走机构的设计及运动学分析

提出了一种新式轮履复合机器人的行走机构的设计方案。对机器人行走机构进行了结构设计,设计包括机器人的轮履变体轮的设计及其传动系统的设计。轮履复合机器人在履带式移动和轮式移动之间的相互转变,使得机器人具有在正常路面的高机动性以及在复杂路面的高通过性.同时,机器人还具有机构可重构、体积小等特点。最后,对机器人轮式行走和履带方式行走特别是履带方式越沟壑、爬斜坡、上台阶作了运动学分析,为后续机器人的研究提供了理论基础。     

曲柄滑块机构运动精度的概率分析与计算

利用矩阵分析理论建立了曲柄滑块机构精度分析的一般模型,利用状态函数建立了曲柄滑块机构运动精度的概率分析模型,以对心曲柄滑块机构为具体对象,建立了曲柄滑块机构运动输出精度模型及其概率分析计算模型。算例分析表明:在给定的设计精度下,对心曲柄滑块机构在不同的运动状态有着不同的运动误差和不同的运动可靠度。模型可以定量地给出曲柄滑块机构在不同运动状态下的失效概率,对曲柄滑块机构的设计与制造具有应用价值。     

复杂与封闭行星齿轮机构运动学分析的新方法

介绍了一种复杂和封闭行星齿轮机构运动学分析的新方法——分析几何法。论文首先陈述了新方法的主要内容,并说明了使用新方法进行运动学分析的系统化步骤;随后通过两个复杂行星齿轮机构：新型指南车和6-杆封闭机构的分析,详细演示了分析几何方法的使用;最后对计算过程与结果的呈现,与常规分析方法进行了简单对比,并讨论了分析几何方法所具有的分析能力。结果表明：分析几何法相较传统的基于代数的方法,全部运动学可一次求解,具有直观,简便的特点。分析过程使用Mathematica计算软件包编制程序自动完成。     

极坐标下逐点比较法的直线插补

在旋臂式结构的机械加工装置中采用极坐标图形插补具有很多优点.结合旋臂式数控切割机床,采用逐点比较法的原理,对极坐标系统下的直线插补理论及其算法做了详细的探讨,并给出了递推公式和程序框图.还对如何采用MCS-51单片机编程实现作了简单介绍.     

平面连杆机构运动误差综合的研究（Ⅱ）─—典型尺寸曲柄摇杆机构的运动误差特性

提出了机构运动误差特性的评价指标，揭示了曲柄摇杆机构尺寸类型与其运动误差特性之间的内在联系，编制了相应的图谱，从而为考虑运动精度要求的机构尺寸类型的选定提供了依据和方法．     

对称曲线槽槽轮机构运动分析与仿真

在AutoCAD2000的基础上,利用VBA作为开发工具,论述对称曲线槽槽轮机构运动学分析的方法及其动画仿真 的实现过程。该程序界面友好,方便直观,既可用于工程实际,又可满足教学需要。     

轿车乘坐舒适性及悬架系统匹配与优化

对车辆悬架系统偏频特性进行快速的分析和匹配,有着重要的工程实际意义.因此基于车辆平顺性,建立了适用于车辆振动分析的基本力学模型,以垂向振动频率和俯仰振动频率为评价指标,针对国产某车型,对其悬架系统前、后偏频进行优化,提出了改善车辆平顺性的优化方案.优化结果和试验结果相比较,说明了此种优化方法快速有效.     

3-RPS型并联机器人的运动学及动力学分析

并联机器人的运动学分析及动力分析是一个非常复杂的计算过程,自编程序的通用性和正确性需要大量的验证.ADAMS软件是一个大型的仿真软件.以ADAMS软件为基础,针对并联机器人建立了分析用模型,给出一种基于ADAMS的的运动学及动力学分析方法.这种方法不需大量的数学计算和计算机语言编程工作,非常快捷、方便、准确.从分析结果可以看出这种分析方法所得到的解完全可以用到实际中.     

导弹舱段六自由度并联调姿托架设计及运动学分析

针对导弹舱段对接主要依靠手工作业的现状,设计一种六自由度并联调姿托架,可完成舱段偏航、俯仰、自转全姿态位置调整,实现舱段自动化、高效率对接.首先建立调姿托架的三维模型并对其结构进行介绍;其次对模型进行运动学理论分析,得到了自由度、运动学方程及其正反解,并利用ADAMS软件对调姿托架进行运动学仿真,获得自由度计算结果以及...     

任意平面机构运动、动力分析的一种新方法（二）─—机构运动及动力分析

本文以第一部分［１］为基础，通过机构单开链单元运动、动力学分析模型的组合，建立了复杂闭链机构维数最低的位置分析方程组，导出了一般平面闭链机构速度、加速度分析的显表达式，进而由虚功原理与达朗伯原理方便地建立起一般平面闭链机构的显式动力学方程并简化了机构的动态静力分析。公式推导简明、便于编程。最后给出了计算示例。     

变工况条件下多万向铰驱动轴系的运动特性分析

为研究偏斜轴系过渡过程中的振动及其稳定性,研究了多万向铰轴系在变工况条件下的运动学特性.应用坐标变换的方向余弦矩阵法导出了双铰系统和多铰系统的角速度和角加速度波动的解析表达式,分析了主动轴加速情况下从动轴运动的变化规律,并进行了计算与分析,结果表明:与定常工况相比,变工况(主动轴加速)导致更复杂的运动波动;运动波动周期随时间增大变短;随着主动轴角加速度的增大,角速度和角加速度的波动周期变短,角加速度波动幅度增大;中间轴两端轴叉共面比中间轴两端轴又垂直引起的运动波动幅度小.研究工作对进一步确定万向铰驱动的偏斜轴系的动力学行为具有重要的意义.     

Dynamic characteristics of a generalised suspension system

The paper studies analytically the free vibration of a generalised suspension system. The system is composed of a rigid body with the symmetric shape about its centroid and two symmetrically inclined massless strings with infinite axial stiffness. The two hanging points have horizontal and vertical elastic supports. The rigid body is eccentrically acted by horizontal, vertical and rotational springs. A typical application of the model is to represent a section of cable suspended bridges involving the lateral vibration of small amplitude. The governing differential equations with three degrees-of-freedom are derived where the effect of gravitational potential is considered. The static equilibrium position is determined simultaneously. When the elastic constraints are applied at the centroid of the rigid body, the vibration modes of the system can be divided into symmetric and antisymmetric ones which are studied independently. The analytical expressions of natural frequencies for some special cases are also provided. The effects of various parameters, especially the length and inclined angle of the strings, on the natural frequencies of the system are examined. Some useful conclusions are obtained. Simple model demonstration and verification are conducted to verify some findings in the paper.     

用点形图描述运动链的结构

阐述了顶点的邻接线及闭合形的邻接角等新概念 ,论述了用点形图及转置图描述运动链拓扑结构、距离尺度结构和相对位形尺度结构的方法。本研究表明 :点形图可以描述任何运动链的拓扑结构和尺度结构     

Kinematic configuration analysis of planar mechanisms based on basic kinematic chains

According to the single-link transformation principle, and based on the topological characteristic investigations to planar closed kinematic chains (PCKCs), a general study of the kinematic configuration analysis of planar mechanisms with R-pairs is conducted in this paper. Firstly, two new concepts, contract link distance sequence and basic link group code sequence, are defined, and a novel approach for identification of multi-bar basic kinematic chains (BKCs) within the kinematic chain left from the single-link transformation is proposed. Then, another two concepts, weight code and similarity code, are defined for aid to link similarity judgment and two judgment theorems are proposed as well. As a further step, weight code or similarity code of the transformed single-link will be employed for kinematic configuration analysis situation judgment. Finally, corresponding unified constraint equations are set up and solved with coefficient homotopy method, on the basis of aforementioned analysis results. The study shows that the method is reliable and effective, and it is especially applicable for the kinematic configuration analysis problem of PCKCs with multi-bars and multi-freedoms.