Kinematic Analysis of Spatial Mechanisms by Means of Screw Coordinates. Part 1—Screw Coordinates

1971 ◽  
Vol 93 (1) ◽  
pp. 61-66 ◽  
Author(s):  
M. S. C. Yuan ◽  
F. Freudenstein
Keyword(s):  
Numerical Methods ◽  
Motion Analysis ◽  
Kinematic Analysis ◽  
Rigid Bodies ◽  
Spatial Mechanisms ◽  
Computer Aided

The concept of screw coordinates is developed in terms of motor algebra, and applied to the kinematics and statics of rigid bodies, in particular to the computer-aided motion analysis of spatial mechanisms. The laws of the composition and transformation of screw coordinates and their application to the kinematics and statics of rigid bodies are developed. These results form the basis for the development of numerical methods for the kinematic analysis of spatial mechanisms.

A Dual Number Approach to the Kinematic Analysis of Spatial Linkages With Dimensional and Geometric Tolerances

2004 ◽  
Author(s):  
Emanuele Cecchini ◽  
Ettore Pennestri` ◽  
Roberto Stefanelli ◽  
Leonardo Vita
Keyword(s):  
Kinematic Analysis ◽  
Tolerance Analysis ◽  
Rigid Bodies ◽  
Kinematic Modeling ◽  
Spatial Mechanisms ◽  
Analysis And Synthesis ◽  
Spatial Linkages ◽  
Joint Clearances ◽  
First Time ◽  
Cardan Joint

Design robustness is somewhat connected to tolerances. In fact, the lower is the sensitivity of the kinematic function to the deviations of manufacturing process, the higher is the robustness of the design. In this investigation is described a tolerance analysis method based on dual vectors kinematic modeling of spatial linkages and on Monte Carlo simulation of the random variables. In the present analysis the hypothesis of rigid bodies is valid and only kinematic variables are considered in output. The method is applied to a Cardan joint modelled as an RCCC linkage with main dimensions considered as stochastic variables with Gaussian distribution. Dual vectors are well known in kinematic analysis and synthesis of spatial mechanisms. When compared with traditional vectorial methods, dual vectors show an enhanced capability to model misalignments among kinematic pairs axes. Although this is not the first time that dual vectors are used for the kinematic and dynamic analysis of spatial mechanisms with manufacturing errors, the present use of dual vectors to model joint clearances seems somewhat novel.

CONSTRUCTION OF SCREW GEOMETRY VIA 3-D CAD SYSTEM FOR THE ANALYSIS AND SYNTHESIS OF SPATIAL MECHANISMS

2000 ◽  
Vol 24 (2) ◽  
pp. 401-413
Author(s):  
F.Z. Chen ◽  
M.J. Tsai
Keyword(s):  
Kinematic Analysis ◽  
Computer Aided Design ◽  
Graphical Method ◽  
Graphic Method ◽  
Efficient Process ◽  
Cad System ◽  
Spatial Mechanisms ◽  
Computer Aided ◽  
Analysis And Synthesis ◽  
Aided Design

This paper investigates the application of computer-aided design and drawing (CAD) software to the kinematic analysis and synthesis of spatial mechanisms based upon screw geometry. The advantages of the graphic method for the synthesis and analysis of mechanisms are straightforward, comprehensive, clearly represented, and easy to correlate to a real mechanism. Using conventional 3-D CAD software, the screw axes and joint axes are constructed as virtual parts. The relationships of joint axes that are constrained by screw geometry are the assembly conditions for the virtual parts in the CAD system. This paper shows that, similar to the synthesis of a planar linkage, the synthesis of a spatial C-C dyad by the graphical method in a CAD system is an efficient process.

Kinematic design and motion analysis of spatial rapier drive mechanisms used in weaving machines

2014 ◽  
Vol 84 (19) ◽  
pp. 2065-2073 ◽  
Author(s):  
Recep Eren ◽  
Mesrur Erturk ◽  
Barıs Hascelik
Keyword(s):  
Motion Analysis ◽  
Kinematic Analysis ◽  
Gear Ratio ◽  
Main Shaft ◽  
Drive Mechanism ◽  
Spatial Mechanism ◽  
Kinematic Design ◽  
Shaft Angle

This paper presents an approach for the kinematic design of a rapier drive mechanism containing a spatial mechanism and analyses rapier motion curve. Kinematic design and analysis equations are derived and then the link lengths of the spatial mechanism are calculated in order to satisfy the critical rapier positions inside and outside the shed. In this way, the portions of one loom revolution, during which the rapiers are inside and outside the shed, are determined. The rapier motion curve is obtained by using kinematic analysis equations. It is shown that the position of the oscillating link in the spatial mechanism and the loom main shaft angle at which the rapier enters the shed have the most significant effect on the rapier motion curve. The gear ratio has also some effect on the rapier motion curve. Different rapier motion curves are obtained by changing these parameters and the suitability of these curves for rapier motion is discussed.

Kinematic Analysis of Spatial Mechanisms by Means of Screw Coordinates. Part 2—Analysis of Spatial Mechanisms

1971 ◽  
Vol 93 (1) ◽  
pp. 67-73 ◽  
Author(s):  
M. S. C. Yuan ◽  
F. Freudenstein ◽  
L. S. Woo
Keyword(s):  
Computer Program ◽  
Kinematic Analysis ◽  
Static Force ◽  
Single Degree Of Freedom ◽  
Numerical Examples ◽  
Spatial Mechanism ◽  
Single Degree ◽  
Spatial Mechanisms ◽  
Torque Analysis ◽  
Basic Concepts

The basic concepts of screw coordinates described in Part I are applied to the numerical kinematic analysis of spatial mechanisms. The techniques are illustrated with reference to the displacement, velocity, and static-force-and-torque analysis of a general, single-degree-of-freedom spatial mechanism: a seven-link mechanism with screw pairs (H)7. By specialization the associated computer program is capable of analyzing many other single-loop spatial mechanisms. Numerical examples illustrate the results.

scholarly journals Conceptual Design and Computational Modeling Analysis of a Single-Leg System of a Quadruped Bionic Horse Robot Driven by a Cam-Linkage Mechanism

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Liangwen Wang ◽  
Weiwei Zhang ◽  
Caidong Wang ◽  
Fannian Meng ◽  
Wenliao Du ◽  
...  
Keyword(s):  
Motion Analysis ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Kinematic Modeling ◽  
Linkage Mechanism ◽  
Vector Method ◽  
Pressure Angle ◽  
End Point

In this study, the configuration of a bionic horse robot for equine-assisted therapy is presented. A single-leg system with two degrees of freedom (DOFs) is driven by a cam-linkage mechanism, and it can adjust the span and height of the leg end-point trajectory. After a brief introduction on the quadruped bionic horse robot, the structure and working principle of a single-leg system are discussed in detail. Kinematic analysis of a single-leg system is conducted, and the relationships between the structural parameters and leg trajectory are obtained. On this basis, the pressure angle characteristics of the cam-linkage mechanism are studied, and the leg end-point trajectories of the robot are obtained for several inclination angles controlled by the rotation of the motor for the stride length adjusting. The closed-loop vector method is used for the kinematic analysis, and the motion analysis system is developed in MATLAB software. The motion analysis results are verified by a three-dimensional simulation model developed in Solidworks software. The presented research on the configuration, kinematic modeling, and pressure angle characteristics of the bionic horse robot lays the foundation for subsequent research on the practical application of the proposed bionic horse robot.

scholarly journals Forward kinematic analysis of a 3-RRRS mechanism with subordinate driving variables using a computer-aided geometric method

2019 ◽  
Vol 16 (4) ◽  
pp. 172988141987066
Author(s):  
Liangwen Wang ◽  
Tuanhui Wang ◽  
Fannian Meng ◽  
Wenliao Du ◽  
Caidong Wang ◽  
...  
Keyword(s):  
Analytical Method ◽  
Kinematic Analysis ◽  
Visual Basic ◽  
Geometric Method ◽  
Kinematics Analysis ◽  
Kinematic Chains ◽  
Computer Aided ◽  
Parameterized Model ◽  
Moving Platform ◽  
Analysis System

The 3-RRRS mechanism (RRRS refers to kinematic pairs of a branched chain consisting of three R pairs (Rotational pairs) and one S pair (Spherical pair), successively) is used between a moving platform and a static platform, through which six-dimensional motion of the moving platform relative to the static platform can be achieved. Selecting six independently drivable joints from nine active joints makes it problematic to deal analytically with the kinematics of the 3-RRRS mechanism. In this article, a novel computer-aided geometric method for kinematic analysis is developed. This method can automatically detect the independently drivable joints for arbitrary kinematic chains. This method can be easily implemented compared to the analytical method of the forward kinematics. Based on the constraint relationship of the 3-RRRS mechanism, a general 3-RRRS mechanism digital model is built in the SolidWorks Application Program Interface embedded Visual Basic environment, in which the platform sizes and active driving angles are driven by the parameterized model, to make the moving platform move to the corresponding pose. After the pose of the moving platform is confirmed, the coordinate system is built in a preliminary sketch. The parameters are measured by the SolidWorks measuring functions, and the pose of the moving platform is obtained by combining homogeneous matrices. Using the computer-aided geometric method, the detailed kinematics formula is not required. The accuracy and efficiency of the computer-aided geometric method were assessed with some examples of kinematic analysis for the 3-RRRS mechanism. The results showed that the proposed method obtained competitive precision and calculation time to the analytical method and is beneficial as a convenient solving process. By using Visual Basic programming, a reachable poses analysis of the mechanism can be merged into the kinematics analysis system of the computer-aided geometric method. The computer-aided geometric method could be widely applied to kinematics analysis of mechanisms.

Sign in / Sign up

Export Citation Format

Share Document