In-Process and On-Machine Measurement of Machining Accuracy for Process and Product Quality Management: A Review

In-process and on-machine measurements are used to evaluate a variety of machining factors and conditions as well as the work done on the machine tool. With the increasing complexity of machining processes and greater requirements for accuracy and precision, the demand for advanced methods for process optimization has also increased. To meet this demand, process quality management (QM) requires an expansion of manufacturing metrology to include comprehensive closed-loop control of the machining process. To eliminate the effects of disturbances on the machining process and adjust the control quantities to optimal values for robustness, in-process and on-machine measurements are very essential. In this paper, we review technical trends in in-process and on-machine measurements for process QM and conventional quality control (QC) of products. Spreading measurement targets and applications are comprehensively reviewed.

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Influence of a closed-loop controlled laser metal wire deposition process of S Al 5356 on the quality of manufactured parts before and after subsequent machining

Production Engineering ◽

10.1007/s11740-021-01030-w ◽

2021 ◽

Author(s):

Dina Becker ◽

Steffen Boley ◽

Rocco Eisseler ◽

Thomas Stehle ◽

Hans-Christian Möhring ◽

...

Keyword(s):

Wall Thickness ◽

Closed Loop ◽

Deposition Process ◽

Metal Wire ◽

Machining Process ◽

Machining Processes ◽

Initial State ◽

Additive Process ◽

Shape Accuracy ◽

Loop Control

AbstractThis paper describes the interdependence of additive and subtractive manufacturing processes using the production of test components made from S Al 5356. To achieve the best possible part accuracy and a preferably small wall thickness already within the additive process, a closed loop process control was developed and applied. Subsequent machining processes were nonetheless required to give the components their final shape, but the amount of material in need of removal was minimised. The effort of minimising material removal strongly depended on the initial state of the component (wall thickness, wall thickness constancy, microstructure of the material and others) which was determined by the additive process. For this reason, knowledge of the correlations between generative parameters and component properties, as well as of the interdependency between the additive process and the subsequent machining process to tune the former to the latter was essential. To ascertain this behaviour, a suitable test part was designed to perform both additive processes using laser metal wire deposition with a closed loop control of the track height and subtractive processes using external and internal longitudinal turning with varied parameters. The so manufactured test parts were then used to qualify the material deposition and turning process by criteria like shape accuracy and surface quality.

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The Study of Closed-Loop Position Control System Based on CNC Processing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.941-944.2243 ◽

2014 ◽

Vol 941-944 ◽

pp. 2243-2246

Author(s):

Xin Zhou

Keyword(s):

Control System ◽

Machine Tools ◽

Closed Loop ◽

Position Control ◽

Machining Accuracy ◽

Closed Loop Control ◽

Loop Control ◽

Nc Machine ◽

Nc Machine Tools ◽

Position Control System

In view of the existing problems of indirect position closed-loop control, a digitized closed-loop control method is presented and a new kind of position control system with fully digitized closed-loop based on that method is developed. In this way, the fully digitized control of cutter trajectory is implemented with the features of digitized driving, digitized measuring and digitized position control, so that the machining accuracy of the NC machine tools is effectively assured. This system has been used on varieties of NC machine tools and very good results have been obtained in the machining of complex precision parts.

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The Impact of Visual Feedback Type on the Mastery of Visuo-Motor Transformations

Zeitschrift für Psychologie ◽

10.1027/2151-2604/a000084 ◽

2012 ◽

Vol 220 (1) ◽

pp. 3-9 ◽

Cited By ~ 4

Author(s):

Sandra Sülzenbrück

Keyword(s):

Empirical Research ◽

Visual Feedback ◽

Closed Loop ◽

Motor Planning ◽

Visual Input ◽

Closed Loop Control ◽

Loop Control ◽

Feedback Type ◽

Effective Use ◽

The Impact

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.

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