scholarly journals Rapid Response Diagnosis of Multi-stage Assembly Process with Compliant non-ideal Parts using Self-evolving Measurement System

Procedia CIRP ◽  
2017 ◽  
Vol 60 ◽  
pp. 38-43 ◽  
Author(s):  
Pasquale Franciosa ◽  
Arnab Palit ◽  
Ferdinando Vitolo ◽  
Darek Ceglarek
Keyword(s):  
Measurement System ◽  
Rapid Response ◽  
Assembly Process ◽  
Multi Stage

Integration and Implementation of an Advanced Measurement System into The Assembly Process in Support of NEAT" Hull Block Construction and Erection"

1993 ◽  
Author(s):  
David L. Malmquist ◽  
Paul Downs ◽  
Dan Sfiligoi ◽  
Wayne Stevenson ◽  
Gerry Flynn ◽  
...  
Keyword(s):  
Measurement System ◽  
Assembly Process ◽  
Block Construction

Tolerance Analysis and Diagnosis Model of Compliant Block Assembly Considering Welding Deformation

2015 ◽  
Author(s):  
Junghyun Lee ◽  
Wooyoung Choi ◽  
Minseok Kang ◽  
Hyun Chung
Keyword(s):  
Tolerance Analysis ◽  
Normal Equation ◽  
Welding Distortion ◽  
Assembly Process ◽  
Accuracy Control ◽  
Mechanical Assembly ◽  
Multi Stage ◽  
Proposed Model ◽  
Diagnosis Model ◽  
Welding Processes

This paper proposes a simplified tolerance analysis and diagnosis model including the effects of welding distortion, for accuracy control in ship block assembly processes. The variation simulation model for tolerance analysis utilizes the concepts of the sources of variation and the compliant mechanical assembly model to include the welding distortions. The proposed model utilizes welding distortion patterns and a transformation matrix to efficiently model the deformation during the joining process. The diagnosis model assumes the multi-stage assemblies and that the variations of previous stages are propagated to the current stage. It calculates the sensitivity; a linear mapping from input parts to output assembly variations, and includes the effects of welding distortion as an additional vector that deviates the assembly variation further. The diagnosis model predicts the quantitative effect of each source of variations to the final assembly’s geometrical variation, based on normal equation and assembly stage’s state space equation model. The proposed model is applied to a realistic block assembly process for validation purpose. The model can effectively simulate the propagation of welding distortion as well as quantitatively identify variation patterns and welding processes throughout the multi-stage assembly process.

Development of a Precision Micro-Assembly Machine for ICF Targets

2012 ◽  
Vol 605-607 ◽  
pp. 1431-1435
Author(s):  
Wen Rong Wu ◽  
Da Hai Yu ◽  
Lin Zhang ◽  
Zu Rong Qiu ◽  
Xin Han Huang
Keyword(s):  
Monitoring System ◽  
Measurement System ◽  
Online Monitoring ◽  
Mathematic Model ◽  
Research Community ◽  
Microscopic Image ◽  
Assembly Process ◽  
Micro Assembly ◽  
On Line ◽  
Online Monitoring System

The Precision Micro-Assembly Machine was developed to manufacture the ICF targets, which have submillimeter-sized components with micrometer sized features. The machine provides simultaneous manipulation of three objects in a 3-cm3 operating arena and can stitch together multiple millimeter-scales operating arenas over distances spanning tens of centimeters with micrometer-level accuracy. In this report, we will discuss the technologies that are merged to help assist the research community with micro-component fabrication. Furthermore, we also present the design of the online monitoring system, which contains two kinds of non-contact measurement system, microscopic image and laser confocal. The online monitoring system can characterize the positions of the target components during the assembly process. The effect and mathematic model of on-line measuring was analyzed. The results of target assembly experiments show position tolerance of the assembly is not more than 10μm.

scholarly journals Performance measurement system implementation in a turbulent operating environment

2016 ◽  
Vol 65 (7) ◽  
pp. 947-958 ◽  
Author(s):  
Sanna Pekkola ◽  
Minna Saunila ◽  
Hannu Rantanen
Keyword(s):  
Performance Measurement ◽  
Measurement System ◽  
Performance Measurement System ◽  
Turbulent Environment ◽  
Content Type ◽  
Design And Implementation ◽  
Multi Stage ◽  
Study Results ◽  
Measurement Design

Purpose The purpose of this paper is to examine how a performance measurement system (PMS) can be designed for small- and medium-sized enterprises (SMEs) operating in a turbulent environment. The current models and frameworks for the design and implementation of a PMS are for large companies; these traditional design and implementation processes are too multi-stage and long term for SMEs operating in a rapidly changing environment. Design/methodology/approach The study constructs a conceptual framework based on the performance measurement and management literature and empirical evidence from a longitudinal case study. Interviews, an analysis of strategic documents and documentation of the prevailing measurement system were conducted. Findings The study results reveal the framework for a flexible PMS design. In the framework, the PMS consists of core permanent measures that control the profitability of the company and supportive measures of the realisation of strategic targets. The supportive measures change and develop along with the strategy. Originality/value The study provides new understanding about the performance measurement design process in SMEs operating in a turbulent environment. The existing literature presents performance measurement design and implementation process models for large organisations, but these frameworks are too multi-stage and long term for SMEs.

scholarly journals A low-noise high dynamic-range time-domain EMI measurement system for CISPR Band E

2011 ◽  
Vol 9 ◽  
pp. 309-315
Author(s):  
C. Hoffmann ◽  
P. Russer
Keyword(s):  
Real Time ◽  
Measurement System ◽  
Time Domain ◽  
Dynamic Range ◽  
Digital Signal ◽  
High Dynamic Range ◽  
Low Noise ◽  
Noise Floor ◽  
Multi Stage ◽  
Analog To Digital Conversion

Abstract. In this paper, a broadband time-domain EMI measurement system for measurements from 9 kHz to 18 GHz is presented that allows for compliant EMI measurements in CISPR Band E. Combining ultra-fast analog-to-digital-conversion and real-time digital signal processing on a field-programmable-gate-array (FPGA) with ultra-broadband multi-stage down-conversion, scan times can be reduced by several orders of magnitude in comparison to a traditional heterodyne EMI-receiver. The ultra-low system noise floor of 6–8 dB and the real-time spectrogram allow for the characterisation of the time-behaviour of EMI near the noise floor. EMI measurements of electronic consumer devices and electric household appliances are presented.

scholarly journals Abstract P-27: The 30S Ribosomal Subunit Assembly Factor Rbfa Plays a Key Role in the Formation of the Central Pseudoknot and in the Correct Docking of Helix 44 of the Decoding Center

2021 ◽  
Vol 11 (Suppl_1) ◽  
pp. S23-S24
Author(s):  
Elena Maksimova ◽  
Alexey Korepanov ◽  
Olesya Kravchenko ◽  
Timur Baymukhametov ◽  
Alexander Myasnikov ◽  
...  
Keyword(s):  
Ribosome Biogenesis ◽  
Ribosomal Subunit ◽  
Coli Strain ◽  
Assembly Process ◽  
Subunit Assembly ◽  
Head Domain ◽  
Multi Stage ◽  
30S Subunit ◽  
Assembly Factor

Background: Ribosome biogenesis is a complicated multi-stage process. In the cell, 30S ribosomal subunit assembly is fast and efficient, proceeding with the help of numerous assembly protein factors. The exact role of most assembly factors and mechanistic details of their operation remain unclear. The combination of genetic modification with cryo-EM analysis is widely used to identify the role of protein factors in assisting specific steps of the ribosome assembly process. The strain with knockout of a single assembly factor gene accumulates immature ribosomal particles which structural characterization reveals the information about the reactions catalyzed by the corresponding factor. Methods: We isolated the immature 30S subunits (pre-30S subunits) from the Escherichia coli strain lacking the rbfA gene (ΔrbfA) and characterized them by cryo-electron microscopy (cryo-EM). Results: Deletion of the assembly factor RbfA caused a substantial distortion of the structure of an important central pseudoknot which connects three major domains of 30S subunit and is necessary for ribosome stability. It was shown that the relative order of the assembly of the 3′ head domain and the docking of the functionally important helix 44 depends on the presence of RbfA. The formation of the central pseudoknot may promote stabilization of the head domain, likely through the RbfA-dependent maturation of the neck helix 28. The cryo-EM maps for pre-30S subunits were divided into the classes corresponding to consecutive assembly intermediates: from the particles with completely unresolved head domain and unfolded central pseudoknot to almost mature 30S subunits with well-resolved body, platform, and head domains and with partially distorted helix 44. Cryo-EM analysis of ΔrbfA 30S particles revealing the accumulation of two predominant classes of early and late intermediates (obtained at 2.7 Å resolutions) allowed us to suggest that RbfA participate in two stages of the 30S subunit assembly and is deeper involved in the maturation process than previously thought. Conclusion: In summary, RbfA acts at two distinctive 30S assembly stages: early formation of the central pseudoknot including the folding of the head, and positioning of helix 44 in the decoding center at a later stage. An update to the model of factor-dependent 30S maturation was proposed, suggesting that RfbA is involved in most of the subunit assembly process.

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