KIDYAN: Computer-aided kinematic and dynamic analysis of planar mechanisms

The paper deals with a method of kinematic and dynamic analyses of planar linkages and describes a general program based on it. Both make use of a theorem saying that every planar mechanism consists of several Assur groups and of one or more driving links. Likewise, the corresponding program is composed of subprograms for the analysis of these groups.Two examples are presented.     

Computer-aided structure synthesis of spatial kinematic chains

This paper presents a new form of structure formula for spatial mechanisms, which is expressed by using N bars with corresponding pair elements rather than by using pairs. The method of computer-aided structure synthesis of multi-loop, multi-degree-of-freedom, spatial kinematic chains is applied, and all possible kinematic chains are calculated under given conditions.     

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.     

On a computationally efficient microcomputer kinematic analysis of the basic linkage mechanisms

Based on the algebraic correspondence between the displacement equations of the plane, spherical and skew four-bar linkages and the plane and skew slider-crank mechanisms, a highly compact, computationally efficient procedure has been developed for a microcomputer kinetmatic analysis of these linkages.     

On the kinematic synthesis of 5-axis spatial mechanisms

In the present study the possibilities of kinematic synthesis of 5-axis spatial mechanisms are explored, in order to elaborate a design method for achieving associated positions and velocities imposed on input and output links. Structural schemes of 3R-2C mechanisms together with the appropriate mathematical algorithms for their synthesis are suggested. In completion one presents a computer-aided procedure for the kinematic systhesis, directly usable by the designer.     

基于网络的机构运动分析及动态仿真系统的研究

提出用Java Applet语言开发基于网络机械系统的新思想,实现在网络环境中对机构进行运动分析和动态仿真.它具有异地远程控制,多用户并发控制等特点.所研制的系统可以用于工程设计和计算机辅助机构运动分析教学.     

An inverse kinematic analysis procedure for flexible open-loop mechanisms

This paper presents the development of a point-oriented kinematic analysis procedure for open-loop mechanisms that includes provision for elastic links. The analysis method is based upon specifying the three-dimensional reference locations of control points that lie at specified locations on the mechanism. An iterative method based upon 4 × 4 transformation matrix techniques is utilized to solve for the values of the joint variables that define the configuration of the mechanism as well as their velocities and accelerations. This is first done with the assumption that the mechanism links are rigid in order to determine the nominal mechanism state for load calculation purposes. Quasi-static loading conditions are assumed in order to calculate the deformed shapes of the links which are then used to reiterate on the position analysis. The method incorporates least-squares to allow the solution when the control point data is underspecified, overspecified or inconsistently specified. Examples are provided in which the analysis procedure incorporating elastic links is applied to the solution of two planar manipulator positioning problems.

Abstract

Dieser Bericht stellt die Entwicklung eines punktorientierten kinematischen Analysesverfahren für Mechanismen mit offenen kinematischen Ketten unter der Berücksichtigung elastischer Komponenten vor.

Das Verfahren beruht auf des Bestimmung der dreidimensionalen Bezugsorte von Kontrollpunkten, die an bestimmten Stellen des Mechanismus liegen. Eine iterative Methode, basierend auf der Anwendung von 4 × 4 Transformationsmatrizen, wird verwendet, um sowohl die allgemeinen Koordinaten, die die Struktur des Mechanismus beschreiben, als auch deren Geschwindigkeiten und Beschleunigungen zu berechnen. Dafür wird zuerst unter der Annahme steifer Verbindungselements der Ausgangszustand für spätere Belastungsuntersuchungen errechnet. Unter bekannten quasistatischen Lastzuständen werden die Verformungen der Glieder ermittelt und für die reiterative Positionbestimmung verwendet. Dieses Verfahren beinhaltet die Methode der kleinsten Quadrate, um eien Lösung auch im Falle unterbestimmter, überbestimmter oder widersprüchlich bestimmter Kontrollpunkte zu ermöglichen.

Die Anwendung dieses Verfahren zur Lösung zweier ebener Positionieraufgaben für Manipulatoren unter Berücksichtigung elastischer Verbindungselemente wird anhand von Beispielen erläutert.     

Computer-aided design in mechanisms

The man-machine dialog is very important for the design process. In this paper a program system, based on the minicomputer KRS 4201 (ROBOTRON), is demonstrated by using an interactive graphical screen. This program system provides the opportunity to analyze and synthesize mechanisms up to 16 links. The application is demonstrated by designing a front-loader-system for a truck. Real-time animation of seven-bar linkages and coupler curves, including velocity and acceleration, are shown.     

A study on completely computer-assisted kinematic analysis of planar link mechanisms

For the purpose of complete computerization of the kinematic analysis of planar mechanisms, an iterative process of analysis has been determined by means of incidence matrices of prime structures. The prime structures have been defined as the structures composed of pin-jointed links that cannot be derived from other structures, and some of them have been introduced together with positional relations of their joints. Moreover, it is shown that kinematic analyses can also be carried out by means of the prime structures.     

空间光学遥感器运动学支撑方案设计与分析

设计了空间光学遥感器的运动学支撑方案,以解决遥感器的安装和精密定位。首先介绍了约束螺旋理论,主要包括螺旋的概念,修正的K-G公式及公共约束和冗余约束的物理意义。然后提出了3-RRR空间并联机构的运动支撑方案,采用约束螺旋求解法分析理想状态各支撑分支对工作平台的自由度约束问题,以及各分支运动链共同作用到工作平台后产生的公共约束和冗余约束,引入实际情况中的微米级铰间隙,分析其对自由度分配的影响,比较理想情况和实际含间隙情况下工作平台具备的过约束数目的差别。最后运用欧拉公式优化杆件结构,优化后支撑杆件采用空心矩形截面,在不影响运动副工作的同时缩短杆件长度,增强支撑结构的稳定性,完成空间遥感器运动学支撑方案设计。实验结果表明:遥感器沿各轴位移都在0.01mm数量级,绕x,y,z轴转角分别为3.95″,1.86″,1.81″,该方案满足了对空间光学遥感器的支撑和定位要求。     

空间连杆机构运动分析可视化

可视化技术可以使空间机构的运动分析更加直观.以空间RSSR机构为例,运用MATLAB、ADAMS等可视化技术,分析机构的可动性,并利用图表和动态图像显示其位移、速度及加速度等计算结果.     

新型增力液压缸的结构与参数设计

设计了一种超高压增力液压缸,有效地减小增力装置的外形尺寸,并提高输出负载力.在功能结构设计上,使增压腔与外部低压回路隔离,采用特殊的密封件实现运动部件的超高压密封.根据超高压的特殊使用要求,进行了输出缸和增压缸的参数设计,并采用有限元软件ANSYS进行了强度校核.     

空间RSSR机构运动分析的研究

以RSSR机构为例研究了运动分析结果的可视化问题,首先使用解析法对RSSR机构建立运动分析模型,得到运动分析方程,并通过Matlab函数绘制了输出构件的角位移、角速度、角加速度图;其次基于SolidWorks平台三维建模,使用COSMOSMotion进行运动仿真,也得到对应的运动分析结果.通过运动分析的结果对比是完全相同的,但是采用三维参数化软件进行机构运动分析方法过程简单方便,是空间机构运动分析的发展方向.     

Some general problems for the correlation analysis of the accuracy of manufacturing elements of kinematic pairs for spatial mechanisms with dependent primary errors

The specific peculiarities of the primary errors of the work surfaces of spatial cam mechanisms are considered. These errors are shown to be random functions, which are stationary in a particular case. For the latter ones, the stationary conditions were formulated and the possible areas of their application in the actual working environment of the manufacturing of mechanisms were shown.     

Dynamics of mechanisms with kinematic rolling pairs

We consider a number of characteristics of friction mechanisms related to continuously rated drives (variators) in which the motion in some kinematic pairs is transmitted by friction forces. It is shown that dynamic equations include nonholonomic constraints under these conditions, so the solution is carried out within the framework of generalized Lagrange equations.     

一种平面基本运动链位置分析的代数求解

采用代数消元方法以一种平面四环基本运动链的位移分析问题进行了求解,由此得到了一个３０次的输入输出方程,最后给出了算例。     

Group kinematic motion decoupling in parallel mechanisms

Parallel mechanisms with six degrees of freedom with full and partial group kinematic motion decoupling are considered. For mechanisms with full group kinematic motion decoupling, direct and inverse kinematic problems are solved in explicit form.     

Computer-aided design of mechanisms: 1984 and beyond

This special issue on computer-aided design of mechanisms has the objective of representing the state-of-the-art in computer-assisted mechanism analysis and synthesis. The events of the past 25 years are reviewed in this article. The brief look at today and the potential future of this fast-growing area are meant to set the stage for this special issue of Mechanism and Machine Theory.     

空间机构位置分析的矢量回归法

本语文给出了一适中矢量回归公式，用来解决空间机构位置分析问题。该方法不需要引入坐标系，计算量小，具有通用性，易于写电算程序，是一种易于掌握的简便方法。