An Uncertainty Analysis Method for Coordinate Referencing in Manufacturing Systems

1995 ◽  
Vol 117 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Y. Shen ◽  
N. A. Duffie
Keyword(s):  
Uncertainty Analysis ◽  
Coordinate Transformation ◽  
Manufacturing Systems ◽  
Coordinate Transformations ◽  
Analysis Method ◽  
Uncertainty Interval ◽  
Coordinate Measurement ◽  
Uncertainty Sources ◽  
Design And Manufacturing ◽  
Coordinate Measurements

Accurate and consistent transformations between design and manufacturing coordinate systems are essential for high quality part production. Fixturing and coordinate measurement are common coordinate referencing techniques which are used to locate points or measurement points on workpiece reference surfaces to establish these coordinate transformations. However, uncertainty sources such as geometric form deviations in workpiece surfaces, tolerances on fixture locators, and errors in coordinate measurements exist. A result is that coordinate transformations established using the locating and measurement points are in herently uncertain. An uncertainty analysis method for coordinate referencing is presented in this paper. The uncertainty interval concept is used to describe essential characteristics of uncertainty sources in coordinate referencing and coordinate transformation relationships. The method is applied to estimating uncertainties in simple and compound coordinate transformation obtained using coordinate referencing in an experimental mold manufacturing system. Results of Monte Carlo simulations are used to show that the uncertainty analysis method gives a consistent and high percentage of coverage in evaluating coordinate referencing in the examples studied.

scholarly journals Evaluation of coordinate measurement uncertainty of parallelism of axes by means of sensitivity analysis method

Mechanik ◽  
2018 ◽  
Vol 91 (12) ◽  
pp. 1136-1139
Author(s):  
Wojciech Płowucha
Keyword(s):  
Sensitivity Analysis ◽  
Measurement Uncertainty ◽  
Theoretical Basis ◽  
The Other ◽  
Analysis Method ◽  
Connecting Rod ◽  
Coordinate Measurement ◽  
Sensitivity Analysis Method ◽  
Coordinate Measurements ◽  
Tolerance Field

The examples of measurement of three variants of the parallelism of the connecting-rod center axes the theoretical basis of a new method for estimating the uncertainty of coordinate measurements. This is a continuation of the article “Estimation of coordinate measurement uncertainty – theoretical fundamentals” (Mechanik 11, 2018). In the first variant, this tolerance field is in the form of a cylinder, in the other two it has the form of a pair of planes. In the examples presented, uncertainty budgets contain six or nine input factors. In all cases, when the axes of the measured holes are parallel to one of the machine axes, only two input factors affect the uncertainty of the measurement of parallelism deviation.

Usability of Web-Based Design and Manufacturing Systems: Case Study of Micro Machining

2005 ◽  
Author(s):  
Hyung-Jung Kim ◽  
Won-Shik Chu ◽  
Hyuk-Jin Kang ◽  
Sung-Hoon Ahn ◽  
Dong-Soo Kim ◽  
...  
Keyword(s):  
Manufacturing Systems ◽  
Processing Time ◽  
Micro Machining ◽  
User Friendliness ◽  
Web Based ◽  
Design And Manufacturing ◽  
Cad Cam ◽  
Machining System ◽  
Web Based System ◽  
The Web

In this paper, web-based design and manufacturing systems are compared with a commercial CAD/CAM system from the point of usability. The web-based systems included in this study were MIcro Machining System (MIMS) and SmartFab. In the MIMS architecture, a 3D model in STL format was read via a web browser, sent to the web server for toolpath planning, and NC codes were generated to be fed back to the designer through the web connection. In the SmartFab system, SolidWorks was used as the design interface with provided modified menus for micro machining. These additional menus were created by SolidWorks API that also provided web-based links to the toolpath planner. In the commercial CAD/CAM case, without using any web connection, SolidWorks or CATIA was used for design, and PowerMill was used as a CAM tool. For each design and manufacturing system, accessibility, user-friendliness, toolpath-reliability, and processing time were compared. Total 91 students tested these systems in undergraduate CAD class, and the feedback showed better performance of the web-based system in accessibility, user-friendliness, and processing time. However, reliability of the web-based system showed necessity of further improvement.

Structural Modification Simulation: Sensitivity Analysis and the Reanalysis of Modified Structure

1991 ◽  
Author(s):  
Debao Li ◽  
Fangze Li ◽  
Peiming Xu
Keyword(s):  
Sensitivity Analysis ◽  
Transfer Function ◽  
Coordinate Transformation ◽  
Degrees Of Freedom ◽  
Structural Modification ◽  
Function Analysis ◽  
Dump Truck ◽  
Analysis Method ◽  
Transfer Function Analysis ◽  
Dynamic Modification

Abstract This paper deals with the dynamic modification simulation of the structure. The expressions of sensitivity analysis of the system with non-proportional damping and proportional damping are derived at first. As for the reanalysis of modified structure, here we deal with the system to which the modification do not cause any change of the degrees of freedom. Transfer function analysis method and the method of twice coordinate transformation are expounded. As a successful example, the modification simulation of the frame of a dump truck is explained.

scholarly journals Estimation of Uncertainty of Coordinate Measurements According to the Type B Method

2010 ◽  
Vol 437 ◽  
pp. 253-257 ◽  
Author(s):  
Władysław Jakubiec
Keyword(s):  
Characteristic Dimension ◽  
Temperature Influence ◽  
Type B ◽  
Uncertainty Component ◽  
Coordinate Measurement ◽  
Analytical Estimation ◽  
Characteristic Points ◽  
Coordinate Measurements ◽  
Estimation Of Uncertainty

The paper describes a new method for analytical estimation of the uncertainty component introduced by the CMM, including temperature influence. The uncertainty is estimated separately for each characteristic (dimension or geometrical deviation) given in the geometrical specification. The uncertainty is calculated directly, i.e. no analysis of the accuracy of determination of particular geometrical elements is performed. The fundamental condition enabling analytical estimation of the uncertainty is assumption that uncertainty of coordinate measurement depends on the differences of coordinates of characteristic points used to calculate particular deviation.

Implementation of Rapid Manufacturing Systems in the Jewellery Industry in Brazil

2011 ◽  
pp. 119-138
Author(s):  
Juan Carlos Campos Rubio ◽  
Eduardo Romeiro Filho
Keyword(s):  
Computer Aided Design ◽  
Manufacturing Systems ◽  
Medium Size ◽  
Manufacturing Processes ◽  
Computer Aided ◽  
Design And Manufacturing ◽  
Cad Cam ◽  
High Production ◽  
Rapid Prototyping And Manufacturing ◽  
Aided Design

This chapter presents the rapid prototyping and manufacturing concepts applied as means to reducing time between jewellery designs and manufacturing process. Different processes on jewellery modelling production are presented. Nowadays, the use of technologies as CAD/CAM - Computer Aided Design and Manufacturing in high production companies are very disseminated. However, the implementation of these resources at the design and manufacturing processes of jewels and fashion accessories, in small and medium size businesses, is still insipient. As reference, is presented the situation observed in small and medium companies located in Minas Gerais, Brazil.

Small Wind Turbine Power Performance Testing with Uncertainty Analysis

2014 ◽  
Vol 875-877 ◽  
pp. 1944-1948
Author(s):  
Wen Lei Bai ◽  
Byun Gik Chang ◽  
Gerald Chen ◽  
Ken Starcher ◽  
David Carr ◽  
...  
Keyword(s):  
Wind Speed ◽  
Uncertainty Analysis ◽  
Wind Turbine ◽  
Performance Testing ◽  
Air Pressure ◽  
Power Performance ◽  
Small Wind Turbine ◽  
Uncertainty Sources ◽  
Measurement Uncertainties

Wind turbine power performance testing consists of power, temperature, air pressure and wind speed measurements collected for this study during which measuring uncertainties are involved. Due to the measurement uncertainties, the results of power performance testing are affected; therefore, it is necessary to consider the measurement uncertainties for evaluating the accuracy of turbine testing. For this purpose of this study, uncertainty analysis for one 5kW wind turbine power performance testing was conducted. The results of uncertainty analysis indicated that the uncertainty negatively affected the validity of conclusions drawn from power performance testing, and the uncertainty sources are various in different wind speed bins.

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