Computational Kinematic Analysis of Higher Pairs with Multiple Contacts

1995 ◽  
Vol 117 (2A) ◽  
pp. 269-277 ◽  
Author(s):  
E. Sacks ◽  
L. Joskowicz
Keyword(s):  
Configuration Space ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Contact Conditions ◽  
Two Degrees Of Freedom ◽  
Kinematic Theory ◽  
Multiple Contacts

We present a computational kinematic theory of higher pairs with multiple contacts, including simultaneous contacts, intermittent contacts, and changing contacts. The theory systematizes single- and multiple-contact kinematic analysis by mapping it into geometric computation in configuration space. It derives the contact conditions, contact functions, and relations between contacts from the shapes and degrees of freedom of the parts. It helps identify common design flaws, such as undercutting, interference, and jamming, that cannot be systematically identified with current methods. We describe a program for the most common pairs: planar higher pairs with two degrees of freedom.

Mechanism design and kinematic analysis of a robotic manipulator driven by joints with two degrees of freedom (DOF)

2018 ◽  
Vol 45 (1) ◽  
pp. 34-43 ◽  
Author(s):  
He Huang ◽  
Erbao Dong ◽  
Min Xu ◽  
Jie Yang ◽  
Kin Huat Low
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Robotic Manipulator ◽  
Simulation Software ◽  
Design Concept ◽  
Two Degrees Of Freedom ◽  
Content Type ◽  
Dc Motors ◽  
Motion Modes ◽  
Physical Prototype

Purpose This paper aims to introduce a new design concept for robotic manipulator driven by the special two degrees of freedom (DOF) joints. Joint as a basic but essential component of the robotic manipulator is analysed emphatically. Design/methodology/approach The proposed robotic manipulator consists of several two-DOF joints and a rotary joint. Each of the two-DOF joints consists of a cylinder pairs driven by two DC motors and a universal joint (U-joint). Both kinematics of the robotic manipulator and the two-DOF joint are analysed. The influence to output ability of the joint in terms of the scale effect of the inclined plane is analysed in ADAMS simulation software. The contrast between the general and the proposed two-DOF joint is also studied. Finally, a physical prototype of the two-DOF joint is developed for experiments. Findings The kinematic analysis indicates that the joint can achieve omnidirectional deflection motion at a range of ±50° and the robotic manipulator can reach a similar workspace in comparison to the general robotic manipulator. Based on the kinematic analysis, two special motion modes are proposed to endow the two-DOF joint with better motion capabilities. The contrast simulation results between the general and the proposed two-DOF joints suggest that the proposed joint can perform better in the output ability. The experimental results verify the kinematic analysis and motion ability of the proposed two-DOF joint. Originality/value A new design concept of a robotic manipulator has been presented and verified. The complete kinematic analysis of a special two-DOF joint and a seven-DOF robotic manipulator have been resolved and verified. Compared with the general two-DOF joint, the proposed two-DOF joint can perform better in output ability.

Approximation and Control of Curvilinear Shapes via Deployable Mechanisms With Two Degrees of Freedom

2014 ◽  
Author(s):  
Shengnan Lu ◽  
Dimiter Zlatanov ◽  
Xilun Ding ◽  
Rezia Molfino ◽  
Matteo Zoppi
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Geometric Shape ◽  
Large Area ◽  
Two Degrees Of Freedom ◽  
New Device ◽  
Deployable Mechanism ◽  
Two Parameters ◽  
And Control ◽  
Physical Boundary

This paper proposes a multi-unit mechanism, which can be used to approximate, with two independent degrees of freedom, the shape of the geometric outline of an arbitrarily large area. The new device is a variant of a recently introduced planar deployable mechanism with two uncoupled degrees of freedom, built from identical units, each combining Sarrus and scissor linkages. Similar units, but with varying sizes, are used in the new device, which is able to change its elliptical physical boundary by varying independently the two parameters in the standard ellipse equation. The size and placement of the deployable units and their links are analyzed and selected for getting the expected geometric shape. The relationships between the number of dividing lines and the approximating accuracy and the degree of overconstraint, respectively, are calculated. A similar deployable mechanism controlling a hyperbola is also outlined. Kinematic analysis and simulated models show that the mechanisms can be used to approximate geometric curves, as desired.

Creative Design of an Elliptical Trainer with Two Degrees of Freedom

2008 ◽  
Vol 36 (4) ◽  
pp. 284-293 ◽  
Author(s):  
Hsin-Sheng Lee
Keyword(s):  
Range Of Motion ◽  
Mechanism Design ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
Teaching Tool ◽  
Creative Design ◽  
Two Degrees Of Freedom ◽  
Design Requirements ◽  
Number Synthesis

The elliptical trainer is a widely used piece of equipment for fitness and rehabilitation. An elliptical trainer with seven links and eight joints, and two degrees of freedom, can have its range of motion adjusted to match the user's stature, and the user can obtain different athletic effects. It allows for more adjustment than an elliptical trainer with one degree of freedom. In this paper, we refer to the present patents that specify the design requirements and constraints for an elliptical trainer. We then use Yan's creative mechanism design methods, which include generalized principles, number synthesis, specialization, and particularization, to obtain a practicable structure for an elliptical trainer with two degrees of freedom. We obtained five alternative kinds of mechanism. We chose one of them for a simulated kinematic analysis, and manufactured the prototype. This paper can serve not only as a reference for the development of fitness equipment but also as a teaching tool for creative mechanism design courses.

The scientific bases of autocontrol with vibration phase for a resonance beating-vibration system with two degrees of freedom driven by debalances

1996 ◽  
Vol 18 (2) ◽  
pp. 43-48
Author(s):  
Tran Van Tuan ◽  
Do Sanh ◽  
Luu Duc Thach
Keyword(s):  
Degrees Of Freedom ◽  
Regulation System ◽  
Vibration System ◽  
Two Degrees Of Freedom ◽  
System Operating

In the paper it is introduced a method for studying dynamics of beating-vibrators by means of digital calculation with the help of the machine in accordance with the needs by the helps of an available auto regulation system operating with high reability.

scholarly journals Two Degrees of Freedom Slip Controller with Lateral Torque Distribution

2020 ◽  
Vol 53 (2) ◽  
pp. 14450-14455
Author(s):  
Wolfgang Degel ◽  
Stefan Lupberger ◽  
Dirk Odenthal ◽  
Naim Bajcinca
Keyword(s):  
Degrees Of Freedom ◽  
Torque Distribution ◽  
Two Degrees Of Freedom
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