Kinematic Synthesis With Contact Direction and Curvature Constraints on the Workpiece

2007 ◽  
Author(s):  
Nina Patarinsky Robson ◽  
J. Michael McCarthy
Keyword(s):  
Rigid Body ◽  
Normal Direction ◽  
Kinematic Synthesis ◽  
Moving Body

In this paper, we consider the synthesis of a planar RR chain that guides a rigid body, or workpiece, such that it does not violate normal direction and curvature constraints imposed by contact with objects in the environment. These constraints are transformed into conditions on the velocity and acceleration of points in the moving body. We use this to formulate the synthesis equations for an RR chain, which are solved by algebraic elimination. An example of the design of a planar RR linkage and a four-bar chain in which the coupler maintains in contact with two objects in two locations is used to illustrate the results.

Geometric Design of Spherical Serial Chains With Curvature Constraints in the Environment

2011 ◽  
Author(s):  
Nina Robson ◽  
Anurag Tolety
Keyword(s):  
Rigid Body ◽  
Robot Manipulator ◽  
Normal Direction ◽  
Geometric Design ◽  
Failure Recovery ◽  
Kinematic Synthesis ◽  
Synthesis Techniques ◽  
Moving Body ◽  
Trajectory Interpolation ◽  
Serial Chains

This paper builds up on recent results on planar kinematic synthesis with contact direction and curvature constraints on the workpiece. We consider the synthesis of spherical serial chains to guide a rigid body, such that it does not violate normal direction and curvature constraints imposed by contact with objects in the environment. We show how to derive these constraints from the geometry of the task and transform them into conditions on velocity and acceleration of points in the moving body to obtain synthesis equations which can be solved by algebraic elimination. Trajectory interpolation formulas yield the movement of the chain with the desired contact properties in each of the task positions. An example shows the application of the developed theory to the failure recovery of a robot manipulator, using kinematic synthesis techniques.

Geometric design of planar mechanisms based on virtual guides for manipulation

Robotica ◽  
2015 ◽  
Vol 34 (12) ◽  
pp. 2653-2668 ◽  
Author(s):  
Nina Robson ◽  
Shramana Ghosh
Keyword(s):  
Rigid Body ◽  
Closed Loop ◽  
Normal Direction ◽  
Assistive Technologies ◽  
Paper Briefly ◽  
Planar Mechanisms ◽  
Kinematic Synthesis ◽  
Kinematic Chains ◽  
Moving Body ◽  
Mechanical Linkage

SUMMARYThis paper presents recent results and applications of our planar kinematic synthesis of serial and parallel linkages to guide a rigid body, such that it does not violate normal direction and curvature constraints imposed by contact with objects in the environment. The paper briefly reviews the recently developed theory on transforming contact direction and curvature constraints into conditions on velocity and acceleration of certain points in the moving body to obtain synthesis equations which can, subsequently be solved to find the dimensions of a mechanical linkage. The main contribution of the paper is in demonstrating the applicability of the proposed theory to the kinematic synthesis of both open and closed-loop kinematic linkages. We provide preliminary results on the synthesis of kinematic chains based on novel task specifications that incorporate curvature constraints with a variety of applications, such as passive suspensions for small rovers, assistive technologies, as well as grasping.

scholarly journals Kinematic synthesis of planar, shape-changing, rigid body mechanisms for design profiles with significant differences in arc length

2013 ◽  
Vol 70 ◽  
pp. 425-440 ◽  
Author(s):  
Shamsul A. Shamsudin ◽  
Andrew P. Murray ◽  
David H. Myszka ◽  
James P. Schmiedeler
Keyword(s):  
Rigid Body ◽  
Arc Length ◽  
Kinematic Synthesis ◽  
Planar Shape

Kinematic Synthesis of a D-Drive MEMS Device With Rigid-Body Replacement Method

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Paolo Sanò ◽  
Matteo Verotti ◽  
Paolo Bosetti ◽  
Nicola P. Belfiore
Keyword(s):  
Rigid Body ◽  
Experimental Testing ◽  
Micro Electro Mechanical System ◽  
Element Analysis ◽  
Kinematic Synthesis ◽  
Replacement Method ◽  
Rigid Body Model ◽  
Mems Device ◽  
Conjugate Surfaces ◽  
Line Path

In this paper, a microsystem with prescribed functional capabilities is designed and simulated. In particular, the development of a straight line path generator micro electro mechanical system (MEMS) device is presented. A new procedure is suggested for avoiding branch or circuit problems in the kinematic synthesis problem. Then, Ball's point detection is used to validate the obtained pseudo-rigid body model (PRBM). A compliant MEMS device is obtained from the PRBM through the rigid-body replacement method by making use of conjugate surfaces flexure hinges (CSFHs). Finally, the functional capability of the device is investigated by means of finite element analysis (FEA) simulations and experimental testing at the macroscale.

Moving-body simulations using overset framework with rigid body dynamics

2008 ◽  
Vol 78 (5-6) ◽  
pp. 618-626 ◽  
Author(s):  
Roy Koomullil ◽  
Gary Cheng ◽  
Bharat Soni ◽  
Ralph Noack ◽  
Nathan Prewitt
Keyword(s):  
Rigid Body ◽  
Rigid Body Dynamics ◽  
Body Dynamics ◽  
Moving Body

Design of a Continuum Mechanism that Matches the Movement of an Eight-bar Linkage

2020 ◽  
pp. 1-11
Author(s):  
Xueao Liu ◽  
J. Michael McCarthy
Keyword(s):  
Finite Element Analysis ◽  
Rigid Body ◽  
Design Methodology ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Initial Structure ◽  
Element Analysis ◽  
Kinematic Synthesis ◽  
Generic Structure ◽  
Straight Line

Abstract This paper presents a design methodology for mechanisms consisting of a single continuous structure, continuum mechanisms, that blends the kinematic synthesis of rigid-body mechanisms with topology optimization for compliant mechanisms. Rather than start with a generic structure that is shaped to achieve a required force deflection task for a compliant mechanism, our approach shapes the initial structure based on kinematic synthesis of a rigid body mechanism for the required movement, then the structure is shaped using Finite Element Analysis to achieve the required force deflection relationship. The result of this approach is a continuum mechanism with the same workpiece movement as the rigid link mechanism when actuated. An example illustrates the design process to obtain an eight-bar linkage that guides its workpiece in straight-line rectilinear movement. We show that the resulting continuum mechanism provides the desired rectilinear movement. A 210 mm physical model machined from Nylon-6 is shown to achieve 21.5mm rectilinear movement with no perceived deviation from a straight-line.

Software for the Kinematic Synthesis of Coupler-Driven Spherical Four-Bar Mechanisms

2007 ◽  
Author(s):  
Eric M. Grimm ◽  
Andrew P. Murray ◽  
Michael L. Turner
Keyword(s):  
Rigid Body ◽  
Kinematic Synthesis ◽  
Prismatic Joint ◽  
Second Stage ◽  
Typical Scheme ◽  
Four Bar Linkage

A spatial analogue of the Stephenson III six-bar mechanism can be formed by the connection of an SPS chain to the coupler of a spherical four-bar linkage. With the prismatic joint actuated, the spherical four-bar is driven via a force applied directly to the coupler. This linkage is termed the coupler-driven spherical four-bar mechanism, and defines an alternative to the typical scheme of actuating the four-bar via a torque applied at the input link. This paper presents software developed to assist in the kinematic synthesis of these mechanisms. In the first stage of the design, a circuit-defect free spherical four-bar is dimensioned with the capacity to guide a rigid body through two orientations. The second stage of the design is to locate the SPS leg such that the four-bar is smoothly drivable between the orientations.

Kinematic Synthesis of Planar, Shape-Changing Rigid Body Mechanisms for 30P30N Slat Design Profile

2016 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Mohammad Hazrin Ismail ◽  
Shamsul Anuar Shamsudin ◽  
Mohd Nizam Sudin
Keyword(s):  
Rigid Body ◽  
Kinematic Synthesis ◽  
Planar Shape

Design and Prototyping of a Shape-Changing Rigid-Body Human Foot in Gait

2018 ◽  
Author(s):  
Tanner N. Rolfe ◽  
Andrew P. Murray ◽  
David H. Myszka
Keyword(s):  
Rigid Body ◽  
Compliant Mechanisms ◽  
Shape Change ◽  
Dynamic Change ◽  
A Priori ◽  
External Loading ◽  
Loading Conditions ◽  
Kinematic Synthesis ◽  
Human Foot

Traditional ankle-foot devices such as prostheses or robotic feet seek to replicate the physiological change in shape of the foot during gait using compliant mechanisms. In comparison, rigid-body feet tend to be simplistic and largely incapable of accurately representing the geometry of the human foot. Rigidbody mechanisms offer certain advantages over compliant mechanisms which may be desirable in the design of ankle-foot devices, including the ability to withstand greater loading, the ability to achieve more drastic shape-change, and the ability to be synthesized from their kinematics, allowing for realistic functionality without a priori characterization of the external loading conditions of the foot. This work focuses on applying the methodology of shape-changing kinematic synthesis to design and prototype a multi-segment rigid-body foot device capable of matching the dynamic change in shape of the human foot in gait.

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