scholarly journals The Influence of Automated Machining Strategy on Geometric Deviations of Machined Surfaces

2021 ◽  
Vol 11 (5) ◽  
pp. 2353
Author(s):  
Ján Varga ◽  
Teodor Tóth ◽  
Peter Frankovský ◽  
Ľudmila Dulebová ◽  
Emil Spišák ◽  
...  
Keyword(s):  
Control System ◽  
Surface Quality ◽  
Coordinate Measuring Machine ◽  
Geometric Tolerance ◽  
Geometric Tolerances ◽  
Significant Difference ◽  
Geometric Deviations ◽  
Measuring Machine ◽  
Overlap Parameter ◽  
Total Average

This paper deals with various automated milling strategies and their influence on the accuracy of produced parts. Among the most important factors for surface quality is the automated milling strategy. Milling strategies were generated from two different programs, CAM system SolidCAM, with the help of workshop programming in the control system Heidenhain TNC 426. In the first step, simulations of different toolpaths were conducted. Using geometric tolerance is becoming increasingly important in robotized production, but its proper application requires a deeper understanding. This article presents the measurement of selected planes of robotized production to evaluate their flatness, parallelism and perpendicularity deviations after milling on the coordinate measuring machine Carl Zeiss Contura G2. Total average deviations, including all geometric tolerances, were 0.020 mm for SolidCAM and 0.016 mm for Heidenhain TNC 426. The result is significantly affected by the flatness of measured planes, where the overlap parameter of the tools has a significant impact on the flatness of the surface. With interchangeable cutter plate tools, it is better to use higher overlap to achieve better flatness. There is a significant difference in production time, with SolidCAM 25 min and 30 s, and Heidenhain 48 min and 19 s. In accordance with these findings, the SolidCAM system is more suitable for production.

Evaluation of Actual Geometric Tolerances Using Coordinate Measuring Machine Data

1989 ◽  
Author(s):  
W. H. ElMaraghy ◽  
Z. Wu ◽  
H. A. ElMaraghy
Keyword(s):  
Three Dimensional ◽  
Measurement Data ◽  
Simulated Data ◽  
Coordinate Measuring Machine ◽  
Optimization Techniques ◽  
Test Cases ◽  
Tolerance Zone ◽  
Geometric Tolerances ◽  
Measuring Machine

Abstract This paper focuses on the development of a procedure and algorithms for the systematic comparison of geometric variations of measured features with their specified geometric tolerances. To automate the inspection of mechanical parts, it is necessary to analyze the measurement data captured by coordinate measuring machines (CMM) in order to detect out-of-tolerance conditions. A procedure for determining the geometric tolerances from the measured three dimensional coordinates on the surface of a cylindrical feature is presented. This procedure follows the definitions of the geometric tolerances used in the current Standards, and is capable of determining the value of each geometric tolerance from the composite 3-D data. The developed algorithms adopt the minimum tolerance zone criterion. Nonlinear numerical optimization techniques are used to fit the data to the minimum tolerance zone. Two test cases are given in the paper which demonstrate the successful determination of geometric tolerances from given simulated data.

Research on the Design of Motion Control System Based on a Novel 5-DOF PCMM

2010 ◽  
Vol 29-32 ◽  
pp. 2296-2301
Author(s):  
Xiu Long Chen ◽  
Gang Hu ◽  
Xue Yan Jiang ◽  
De Yong Wei ◽  
Yong Sheng Zhao
Keyword(s):  
Control System ◽  
Motion Control ◽  
Coordinate Measuring Machine ◽  
Parallel Machine ◽  
Open Architecture ◽  
Motion Control System ◽  
Precision Measuring ◽  
Motion Control Card ◽  
Visual Basic6.0 ◽  
Measuring Machine

A novel 5-Degree of Freedom PCMM (parallel coordinate measuring machine) was proposed, and its motion control system was designed. Compared with the other structural PCMMs, the structure feature of proposed PCMM was described. Then its motion control system was designed with the modularized and open architecture. The controlled scheme of hardware, which based on PC, PMAC motion control card and the precision measuring probe, was developed. The software of the motion control system was written by Visual Basic6.0 language. Finally, the process of motion control for 4-UPS-UPU PCMM was proposed. The new method above for design of motion control system is simple and effective, and may be applied to other parallel machine.

scholarly journals The Off-Line Simulation on Measuring through Software PC-DMIS CAD++ V4.3

2021 ◽  
Vol 11 (14) ◽  
pp. 6556
Author(s):  
Vladimír Rudy ◽  
Marián Králik ◽  
Peter Malega ◽  
Naqib Daneshjo
Keyword(s):  
Coordinate System ◽  
Coordinate Measuring Machine ◽  
Mutual Position ◽  
Base System ◽  
Technical Standard ◽  
Coordinate Systems ◽  
Global Performance ◽  
Geometric Deviations ◽  
Measuring Machine ◽  
Geometric Deviation

The article analyses and evaluates the ever-important topic of assessing geometric deviation of tolerated formations related to bases with the usage of coordinate measuring machines. The basic system for off-line simulation consists of the coordinate planes of a component’s coordinate system. At the beginning of the measurement, the coordinate system is created by the “3–2–1“alignment. Due to production deviations in real surfaces of the component, each measurement generates mutually different coordinate systems, which is well proven by the experiment on measuring with a coordinate measuring machine DEA Global Performance 12.22.10. An integral part of the article is also the quantification of geometric deviations of ideal tolerated formations related to bases, the estimate of the uncertainty of measurement arising from the placement of points in defining the base system, and the effect of such uncertainty upon the interval of satisfactory values in conformity with the STN EN ISO 14253-1 technical standard. The article also includes a proposal measure in order to ensure the reproducibility of defining the mutual position of coordinate systems.

A Solid Boundary Based Tolerance Representation Model

1992 ◽  
Author(s):  
S. Liu ◽  
Z. Dong
Keyword(s):  
Geometric Modeling ◽  
Coordinate Measuring Machine ◽  
Solid Boundary ◽  
Solid Model ◽  
New Approach ◽  
Part Geometry ◽  
Geometric Tolerances ◽  
Design And Manufacturing ◽  
Boundary Face ◽  
Measuring Machine

Abstract An ambiguous representation of design geometry and its allowed variation is essential to design and manufacturing analysis tools using geometric modeling. In this paper, a new approach for modeling and representing mechanical tolerances, using information embedded in the solid model, is introduced. The work focuses on mathematical mapping between the nominal and variant configurations of design geometry, using boundary face-based model variables. The method identifies the relation between the errors of part geometry, represented by a solid model and measured using a coordinate measuring machine, and the tolerances, specified by dimensioning and tolerancing standards. The work is of benefit in understanding of the fundamental nature of geometric errors and tolerances; it guides the specification of dimensional and geometric tolerances; and, contributes to automated mechanical tolerancing in a solid modeling based system.

Best Fit Uncertainty Analysis for Computing Geometric Tolerances

1997 ◽  
Author(s):  
Hong-Tzong Yau
Keyword(s):  
Sample Size ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Point Location ◽  
Geometric Tolerances ◽  
Surface Deviation ◽  
Measuring Machine ◽  
Point Data ◽  
Geometric Variables ◽  
Best Fit

Abstract In computing geometric tolerances using point data from a coordinate measuring machine (CMM), a best fit process needs to be carried out to bring the measurement data to the coordinate system of the substitute geometry. The measurement data does not precisely conform to the substitute geometry. It involves errors from machining as well as measurement itself. With this error-carrying measurement data, the best fit result contains uncertainties which in turn reduce the accuracy of the evaluated tolerances. In this paper, a model is proposed to estimate the best fit uncertainties caused by surface deviation, point location, and CMM sample size. The model was verified by simulation and experiment. To explore factors that affect the uncertainty variations, geometric variables that influence the uncertainties were first studied. Then, to understand the effect of point location on the uncertainty, optimization using the conjugate gradient method was developed to find the best measurement locations by minimizing the total uncertainties. In addition, simulations showed that the uncertainty is inversely proportional to the squared root of the number of points. This result can be used to predict the CMM sample size that will control the best fit uncertainty under certain tolerances.

scholarly journals In Vitro Comparative Evaluation of Different Types of Impression Trays and Impression Materials on the Accuracy of Open Tray Implant Impressions: A Pilot Study

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Sonam Gupta ◽  
Aparna Ichalangod Narayan ◽  
Dhanasekar Balakrishnan
Keyword(s):  
Reference Model ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Impression Material ◽  
Impression Materials ◽  
Significant Difference ◽  
Different Types ◽  
Measuring Machine ◽  
The Difference

Purpose. For a precise fit of multiple implant framework, having an accurate definitive cast is imperative. The present study evaluated dimensional accuracy of master casts obtained using different impression trays and materials with open tray impression technique.Materials and Methods. A machined aluminum reference model with four parallel implant analogues was fabricated. Forty implant level impressions were made. Eight groups (n=5) were tested using impression materials (polyether and vinylsiloxanether) and four types of impression trays, two being custom (self-cure acrylic and light cure acrylic) and two being stock (plastic and metal). The interimplant distances were measured on master casts using a coordinate measuring machine. The collected data was compared with a standard reference model and was statistically analyzed using two-way ANOVA.Results. Statistically significant difference (p<0.05) was found between the two impression materials. However, the difference seen was small (36 μm) irrespective of the tray type used. No significant difference (p>0.05) was observed between varied stock and custom trays.Conclusions. The polyether impression material proved to be more accurate than vinylsiloxanether impression material. The rigid nonperforated stock trays, both plastic and metal, could be an alternative for custom trays for multi-implant impressions when used with medium viscosity impression materials.

Modeling of Surfaces Subject to Orientation Tolerances

2010 ◽  
Author(s):  
Stefano Petro` ◽  
Giovanni Moroni
Keyword(s):  
Signature Analysis ◽  
Form Error ◽  
Specific Process ◽  
Geometric Tolerance ◽  
Geometric Tolerances ◽  
Inspection Strategy ◽  
Geometric Deviations ◽  
Strategy Planning ◽  
Tolerance Verification

Most of products may be manufactured by different processes. However, different process will yield slightly different products. In particular, similar geometric deviations will characterize parts produced by a specific process. It may then be stated that parts show a “manufacturing signature”, i.e. parts manufactured by the same manufacturing process will show similar, but not identical, local geometric deviations. Signature analysis has several applications, including process monitoring, tolerancing, inspection strategy planning for geometric tolerance verification, and failure identification. In past years, several signature models have been proposed for form error. However, models proposed so far are not adequate to describe the signature when orientation, location and run-out tolerances are of interest. These geometric tolerances involve a toleranced feature, plus at least one datum feature, so relation between these feature is relevant. In this work, a methodology for simultaneously modeling both toleranced and datum features will be proposed. The overall model will be constituted by a model for the toleranced feature, a model for the datum feature(s), and a model for the relation between toleranced and datum feature. A case study will be proposed involving orientation tolerances.

The Study on Position Accuracy of Micro-Coordinate Measuring Machine

2008 ◽  
Author(s):  
Chuan Yang ◽  
Qiang Zhao ◽  
Yu-Long Zhao ◽  
Wei-Xuan Jing
Keyword(s):  
Control System ◽  
Pid Control ◽  
Fuzzy Inference ◽  
Coordinate Measuring Machine ◽  
Experimental Results ◽  
Positioning Accuracy ◽  
Loop Control ◽  
Positioning Stage ◽  
Stepper Motors ◽  
Measuring Machine

In order to measure the microcosmic profiles of ultra-smooth surfaces, a high-accuracy noncontact micro-Coordinate Measuring Machine (micro-Coordinate Measuring Machine, micro-CMM) is developed in this paper. The working table of this measurement device is located by a macro-micro dual-drive system. A closed-loop control system, which is composed by a laser interferometer and stepper motors, is adopted to improve the positioning accuracy of the macro-positioning stage. The experimental results show that the positioning accuracy of this system is obviously improved and satisfies the positioning requirement of the macro-positioning stage. Because the positioning accuracy of the flexure-based micro-positioning stage can not satisfy the design requirement under the control of the traditional PID control, A PID control system based on Adaptive Neural-Fuzzy Inference is proposed to improve the control accuracy of the micro-positioning stage. The experimental results show that this system can improve the positioning accuracy of the micro-positioning stage, and basically meets the requirement of the design.

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.

scholarly journals AUTOMATED SYSTEM FOR SURFACE PARALLELISM CONTROL IN PRISMATIC PARTS

2019 ◽  
Vol 2019 (4) ◽  
pp. 27-33
Author(s):  
Сергей Съянов ◽  
Sergey S'yanov ◽  
Анна Ковалева ◽  
Anna Kovaleva Al'bertovna
Keyword(s):  
Control System ◽  
Block Diagram ◽  
Coordinate Measuring Machine ◽  
Control Device ◽  
Automated System ◽  
Automated Control ◽  
Prismatic Parts ◽  
Processing Information ◽  
Measuring Machine ◽  
Device Operation

An automated device for deviation control from parallelism of surfaces in prismatic parts is described. The device is an inexpensive analog of a coordinate measuring machine and allows facilitating and accelerating considerably a process of measurement and processing information obtained in comparison with manual labor. There is presented an assembly drawing of an automated control device and also a structural and a block diagram of the control system for an automated control device. A description of elements of the control system and an automated control device is given, a principle of automated control device operation is de-scribed. To control measurements by a computer there is developed an application by LabVIEW graphic pro-gramming means.

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