scholarly journals A New Method of Relative Coordinate-and-Time Determination

1993 ◽  
Vol 156 ◽  
pp. 427-431
Author(s):  
V.S. Gubanov ◽  
Z.M. Malkin ◽  
N.I. Solina
Keyword(s):  
Reference Frame ◽  
New Method ◽  
Radio Interferometry ◽  
Relative Coordinate ◽  
Time Determination ◽  
Clock Comparison

The paper deals with the relative coordinate-and-time determination in a ground based reference frame by using the NAVSTAR/GLONASS radio interferometry and duplex clock comparison techniques.

A Synthesis Method for Placing Workpieces in RPR Planar Robotic Workcells in Which Large Rotations Are Required at the Workpiece

1996 ◽  
Author(s):  
K. D. Chaney ◽  
J. K. Davidson
Keyword(s):  
Reference Frame ◽  
Synthesis Method ◽  
Analytical Representation ◽  
New Method ◽  
Two Dimensional ◽  
End Effector ◽  
Radial Location ◽  
Practical Applications ◽  
Full Turn ◽  
Large Rotations

Abstract A new method is developed for determining both a satisfactory location of a workpiece and a suitable mounting-angle of the tool for planar RPR robots that can provide dexterous workspace. The method is an analytical representation of the geometry of the robot and the task, and is particularly well suited to applications in which the task requires large rotations of the end-effector. It is determined that, when the task requires that the end-effector rotate a full turn at just two locations and when the first or third joint in the robot is rotatable by one turn, then the radial location of the workpiece is fixed in the workcell but its angular location is not fixed. When the mounting-angle of the tool is also a variable, the method accommodates tasks in which the tool must rotate a full turn at three locations on the workpiece. The results are presented as coordinates of points in a two-dimensional Cartesian reference frame attached to the workcell. Consequently, a technician or an engineer can determine the location for the workpiece by laying out these coordinates directly in the workcell. Example problems illustrate the method. Practical applications include welding and deposition of adhesives.

scholarly journals On Manipulation of Objects in Three-Fingered Grasp

1995 ◽  
Vol 117 (4) ◽  
pp. 561-565 ◽  
Author(s):  
D. P. Chevallier ◽  
S. Payandeh
Keyword(s):  
Reference Frame ◽  
New Method ◽  
Inner Product ◽  
Product Spaces ◽  
End Effector ◽  
Inner Product Spaces ◽  
Contact Points ◽  
Fixed Reference ◽  
Fine Manipulation

Manipulation of the grasped object is defined as the ability of the mechanical end-effector to create an instantaneous motion of the object with respect to a fixed reference frame (e.g., palm reference frame). This class of manipulation is usually referred to as the fine manipulation whereas a collection of all these instantaneous motions of the object is referred to as the gross manipulation. This paper presents a new method where for a given desired twist of the grasped object, the instantaneous motions of the fingertips can be determined. The results of the paper are divided into two parts. First, for the case where the motion of the object is created through motions of the fingertip in off-tangent planes to the object at the contact points. Second, where a class of motion of the grasped object is achieved through motions of the fingertips which are restricted to the tangent planes. The method of this paper utilizes screw geometry, inner product spaces and information regarding grasp configuration. The method is also illustrated through examples.

A new method for arrival time determination of impact signal based on HHT and AIC

2017 ◽  
Vol 86 ◽  
pp. 177-187 ◽  
Author(s):  
Mingzhou Liu ◽  
Jiangxin Yang ◽  
Yanpeng Cao ◽  
Weinan Fu ◽  
Yanlong Cao
Keyword(s):  
Arrival Time ◽  
New Method ◽  
Time Determination

Datum Planes Based on a Constrained L1 Norm

2015 ◽  
Vol 15 (4) ◽  
Author(s):  
Craig M. Shakarji ◽  
Vijay Srinivasan
Keyword(s):  
Reference Frame ◽  
Convex Surface ◽  
Constrained Minimization ◽  
International Organization ◽  
New Method ◽  
Sampled Data ◽  
L1 Norm ◽  
Original Surface ◽  
Data Points ◽  
American Society

This paper has two major goals. First, we present an algorithm for establishing planar datums suitable for a default in tolerancing standards. The algorithm is based on a constrained minimization search based on the L1 (L1) norm after forming a convex surface from the original surface or sampled points. We prove that the problem reduces to a simple minimization search between the convex surface and its centroid. The data points in the discrete case do not need to have any corresponding weights provided with them, as appropriate weighting is part of the algorithm itself, thereby making the algorithm largely insensitive to nonuniformly sampled data points. Terse mathematica code is included for the reader. The code is sufficient for primary and secondary planar datum fitting as well as a 3-2-1 datum reference frame generation. The second goal of this paper is to compare this new method with several other possible means for establishing datum planes, ultimately showing several appealing characteristics of the proposed algorithm. Since both the International Organization for Standardization (ISO) and American Society of Mechanical Engineers (ASME) standardization efforts are actively working to establish datum plane definitions, the timing of such a study is opportune.

A new method for resolving phase ambiguity in radio interferometry using Earth rotation synthesis

2021 ◽  
Vol 21 (7) ◽  
pp. 167
Author(s):  
Huan Zhou ◽  
De-Zhen Xu ◽  
Jian-Guo Yan ◽  
Shao-Wu Chen ◽  
Hai-Tao Li
Keyword(s):  
Earth Rotation ◽  
New Method ◽  
Radio Interferometry ◽  
Phase Ambiguity

The Method of Surveying Concealment Engineering Control Points ITRF Coordinates Based on Gyro Orientation

2015 ◽  
Vol 744-746 ◽  
pp. 1709-1713
Author(s):  
Ji Feng Wu ◽  
Zhi Qiang Yang ◽  
Zhen Shi ◽  
Jian Hua Yang
Keyword(s):  
Reference Frame ◽  
New Method ◽  
Control Points ◽  
Gps Survey ◽  
Engineering Control

In the modern geodesy and precise engineering surveying, we often choose ITRF reference frame as the measurement benchmark for research. In some special projects, however, it is difficult to directly get the coordinates of points by GPS, and the visibility conditions between points have also been limited. According to this problem, we propose a new method combining GPS survey and gyrostatic orientation technology, to access the ITRF coordinates of control points indirectly, and analysis and research the related important issues.

An Improved L1 Based Algorithm for Standardized Planar Datum Establishment

2014 ◽  
Author(s):  
Craig M. Shakarji ◽  
Vijay Srinivasan
Keyword(s):  
Reference Frame ◽  
Convex Surface ◽  
Constrained Minimization ◽  
New Method ◽  
Discrete Case ◽  
Sampled Data ◽  
L1 Norm ◽  
Original Surface ◽  
Data Points

This paper has two major goals. First, we present an algorithm for establishing planar datums suitable for a default in tolerancing standards. The algorithm is based on a constrained minimization search based on the L1 (L1) norm after forming a convex surface from the original surface or sampled points. We prove that the problem reduces to a simple minimization search between the convex surface and its centroid. The data points in the discrete case do not need to have any corresponding weights provided with them, as appropriate weighting is part of the algorithm itself, thereby making the algorithm largely insensitive to nonuniformly sampled data points. Terse Mathematica code is included for the reader. The code is sufficient for constrained and unconstrained planar fitting as well as a 3-2-1 datum reference frame generation. The second goal of this paper is to compare this new method with several other possible means for establishing datum planes, ultimately showing several appealing characteristics of the proposed algorithm. Since both the ISO and ASME standardization efforts are actively working to establish datum plane definitions, the timing of such a study is opportune.

A Synthesis Method For Placing Workpieces In RPR Planar Robotic Workcells

1998 ◽  
Vol 120 (2) ◽  
pp. 262-268 ◽  
Author(s):  
K. D. Chaney ◽  
J. K. Davidson
Keyword(s):  
Reference Frame ◽  
Synthesis Method ◽  
New Method ◽  
Two Dimensional ◽  
End Effector ◽  
Radial Location ◽  
Practical Applications ◽  
The Third ◽  
Full Turn ◽  
Large Rotations

A new method is used for determining both a satisfactory location of a workpiece and a suitable mounting-angle of the tool for planar RPR robots that can provide dexterous workspace. All three joints of the robot have excursion-limits that bound their displacement. For the purposes of this paper, the third joint, a revolute, permits exactly one full turn. Successful locations for the workpiece are those places where the rotations at each task-axis and the third joint are synchronized. For a fixed mounting angle of the tool, the radial location and orientation of the workpiece are determined by just two 2π-rotations of the tool. When the mounting-angle of the tool is also a variable, the tool can be rotated a full turn at three locations on the workpiece. The method is particularly well suited to applications in which the task requires large rotations of the end-effector. The results are presented as coordinates of points in a two-dimensional Cartesian reference frame attached to the workcell. Consequently, a technician or an engineer can determine the location for the workpiece by laying out these coordinates directly in the workcell. Example problems illustrate the method. Practical applications include welding and deposition of adhesives.

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