Automated Part Centering With Impulse Actuation

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
S. J. Furst ◽  
T. A. Dow ◽  
K. Garrard ◽  
A. Sohn
Keyword(s):  
Measurement Uncertainty ◽  
Performance Modeling ◽  
Voice Coil Motor ◽  
Precision Machining ◽  
Linear Actuator ◽  
Design Performance ◽  
Skilled Operator ◽  
Touch Probe

Centering a part on a spindle for precision machining is a tedious, time-consuming task. Currently, a skilled operator must measure the run-out of a part using a displacement gauge, then tap the part into place using a plastic or rubber hammer. This paper describes a method to automatically center a part on a vacuum chuck with initial run-out as large as 2.5 mm. The method involves measuring the magnitude and direction of the radial run-out and then actuating the part until the part and spindle centerlines are within 5 μm of each other. The run-out can be measured with either a touch probe mounted to a machine axis or an electronic gauge. The part is tapped into place with a linear actuator driven by a voice coil motor. This paper includes an analysis of run-out measurement uncertainty as well as the design, performance modeling, and testing of the alignment actuator. This actuator was employed for part realignment and successfully positioned a hemispherical part with an initial run-out of 1–2.5 mm to within 5 μm of the spindle centerline. This capability shows that the run-out of a part manually placed on flat vacuum chuck can be automatically corrected.

Evaluation of True Position Using Coordinate Measuring Machine

2014 ◽  
Vol 555 ◽  
pp. 511-517
Author(s):  
Roman Budiský ◽  
Marian Králik ◽  
Ján Kost
Keyword(s):  
Measurement Uncertainty ◽  
Coordinate System ◽  
Experimental Evaluation ◽  
Coordinate Measuring Machine ◽  
Coordinate Measuring Machines ◽  
Probe System ◽  
Geometric Deviations ◽  
True Position ◽  
Measuring Machine ◽  
Touch Probe

The article makes a contribution to the ever-important topic of evaluating geometric deviations of tolerated forms related to the datum system using coordinate measuring machines with a touch probe system. The datum system consists of the coordinate system and the coordinates planes. An integral part of the article is the quantification of the true position tolerated form related to the datum system and experimental evaluation of the deviation with calculation of measurement uncertainty, according to STN EN ISO 15530-3.

Realization of a Suspension With Negative Stiffness for High-Performance Vibration Isolation Systems

2003 ◽  
Author(s):  
Takeshi Mizuno ◽  
Takefumi Toumiya
Keyword(s):  
Power Control ◽  
High Performance ◽  
Vibration Isolation ◽  
Control Method ◽  
Voice Coil Motor ◽  
Active Suspension ◽  
Negative Stiffness ◽  
Linear Actuator ◽  
Isolation Systems

A control method of realizing negative stiffness of a specified amplitude is presented for an active suspension device with a linear actuator. It is shown that the derived formula is more general than the formula for zero-power control. The validity of the control method is checked experimentally with an apparatus equipped with a voice coil motor (VCM). A suspension device that has negative stiffness of a specified amplitude is actually realized by the proposed control method. The amplitude of negative stiffness is maintained even when the VCM is flexibly supported.

Computer-Controlled Hrem Alignment Using Automated Diffractogram Analysis

1990 ◽  
Vol 48 (1) ◽  
pp. 532-533
Author(s):  
G.Y. Fan ◽  
O.L. Krivanek
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
The Other ◽  
Full Information ◽  
Resolution Electron ◽  
Skilled Operator ◽  
Automatic Alignment ◽  
High Resolution Electron Microscope ◽  
Computer Controlled ◽  
Recorded Image

Full alignment of a high resolution electron microscope (HREM) requires five parameters to be optimized: the illumination angle (beam tilt) x and y, defocus, and astigmatism magnitude and orientation. Because neither voltage nor current centering lead to the correct illumination angle, all the adjustments must be done on the basis of observing contrast changes in a recorded image. The full alignment can be carried out by a computer which is connected to a suitable image pick-up device and is able to control the microscope, sometimes with greater precision and speed than even a skilled operator can achieve. Two approaches to computer-controlled (automatic) alignment have been investigated. The first is based on measuring the dependence of the overall contrast in the image of a thin amorphous specimen on the relevant parameters, the other on measuring the image shift. Here we report on our progress in developing a new method, which makes use of the full information contained in a computed diffractogram.

National primary standard machine of Shore D hardness scale for metals and Leeb hardness scales

2020 ◽  
pp. 6-10
Author(s):  
A.E. Aslanyan ◽  
E.G. Aslanyan ◽  
S.M. Gavrilkin ◽  
A.S. Doynikov ◽  
A.N. Shchipunov
Keyword(s):  
Measurement Uncertainty ◽  
Primary Standard ◽  
Metrological Characteristics ◽  
National Primary Standard ◽  
Hardness Scale ◽  
Leeb Hardness

The article presents the results of studies to improve the National primary standard machine for hardness of metals on the shore D scale GET 161-2001, which were performed in FSUE “VNIIFTRI” from 2016 to 2018 in accordance with the technical task of Rosstandart.The improvement was carried out in order to ensure the uniformity of hardness measurements on the Leeb scales. The created new parts of the primary standard machine, which are settings for reproducing hardness numbers on the Leeb scales, are considered. Metrological characteristics of the upgraded and adopted National primary standard machine (GET 161-2019) were investigated, the budget of measurement uncertainty was calculated for reproducing hardness numbers on the Leeb scales.

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