Statistics for Spatial Data.

A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

http://www-personal.umich.edu/~ykoren/uploads/Reconfigurable_manufacturing_systems_1999_keynote_paper.pdf

Reconfigurable Manufacturing Systems

https://homepages.fhv.at/hgb/New-Papers/CMAME07_BS07b.pdf

Robust Optimization - A Comprehensive Survey

Introduction to stochastic programming

Evolving paradigms of manufacturing: From mass production to mass customization and personalization

Traditional variation analysis methods, such as Root Sum Square method and Monte Carlo simulation, are not applicable to sheet metal assemblies because of possible part deformation during the assembly process. This paper proposes the use of finite element methods (FEM) in developing mechanistic variation simulation models for deformable sheet metal parts with complex two or three dimensional free form surfaces. Mechanistic variation simulation provides improved analysis by combining engineering structure models and statistical analysis in predicting the assembly variation. Direct Monte Carlo simulation in FEM is very time consuming, because hundreds or thousands of FEM runs are required to obtain a realistic assembly distribution. An alternative method, based on the Method of Influence Coefficients, is developed to improve the computational efficiency, producing improvements by several orders of magnitude. Simulations from both methods yield almost identical results. An example illustrates the developed methods used for evaluating sheet metal assembly variation. The new approaches provide an improved understanding of sheet metal assembly processes.

Variation simulation for deformable sheet metal assemblies using finite element methods

Products made of compliant sheet metals are widely used in automotive, aerospace, appliance and electronics industries. One of the most important challenges for the assembly process with compliant parts is dimensional quality, which affects product functionality and performance. This paper develops a methodology to evaluate the dimensional variation propagation in a multi-station compliant assembly system based on linear mechanics and a state space representation. Three sources of variation: part variation, fixture variation and welding gun variation are analyzed. The proposed method is illustrated through a case study on an automotive body assembly process.

/pdf/modeling-variation-propagation-of-multi-station-assembly-218oa3skn7.pdf

Modeling Variation Propagation of Multi-Station Assembly Systems With Compliant Parts

Fixtures are used to locate and hold workpieces during manufacturing. Because workpiece surface errors and fixture set-up errors (called source errors) always exist, the fixtured workpiece will consequently have position and/or orientation errors (called resultant errors). In this paper, we develop a variational method for robust fixture configuration design to minimize workpiece resultant errors due to source errors. We utilize both first-order and second-order workpiece geometry information to deal with two types of source errors, i.e., infinitesimal errors and small errors. Using the proposed variational approach, other fundamental fixture design issues, such as deterministic locating and total fixturing, can be regarded as integral parts of the robust design. Closed-form analytical solutions are derived and numerical examples are shown. By employing the nonlinear programming technique, simulation software called RFixDesign is developed. This paper presents a new procedure for robust fixture configuration design that contributes especially to fixture designs where deformation is not influential.

A Variational Method of Robust Fixture Configuration Design for 3-D Workpieces

http://www-personal.umich.edu/~ykoren/uploads/Impact_of_manufacturing_system_configuration_on_performance_1998.pdf

S. Jack Hu

Papers

Evolving paradigms of manufacturing: From mass production to mass customization and personalization

Variation simulation for deformable sheet metal assemblies using finite element methods

Modeling Variation Propagation of Multi-Station Assembly Systems With Compliant Parts

A Variational Method of Robust Fixture Configuration Design for 3-D Workpieces

Impact of Manufacturing System Configuration on Performance