scholarly journals A New Method of Distribution of Measurement Points on Curvilinear Surfaces of Products

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2667 ◽  
Author(s):  
Marek Magdziak
Keyword(s):  
New Method ◽  
Measuring System ◽  
Free Form ◽  
Experimental Investigations ◽  
Curvilinear Surface ◽  
Probe Radius ◽  
Correction Process ◽  
Measuring Machine ◽  
Coordinate Measurements ◽  
Free Form Surfaces

The article presents the method of selecting scanning lines along which coordinate measurements, performed by using, e.g., a coordinate measuring machine working in the single point probing mode, of free-form surfaces of measured workpieces may be conducted. Additionally, the proposed method supports the user of a coordinate measuring system during defining the number of measurement points distributed along selected scanning lines, thus deciding on the final distribution of measurement points on a measured surface of a product. The proposed method enables distributing measurement points in the parts of a measured product characterized by the worst quality of manufacturing. Moreover, the new method is very automated, therefore it affects the increase in the efficiency of coordinate measurements. The effect of using the new method is the non-uniform distribution of measurement points located on free-form surfaces. The presented algorithm takes into account the lengths of selected cross-sections of a measured curvilinear surface of an object, its geometrical complexity and the accuracy of the probe radius correction process. The decision regarding the number of measurement points is made on the basis of the accuracy analysis of the calculations of the corrected measurement points obtained during the probe radius correction process and the accuracy of the substitute model representing a measured curvilinear surface. Two methods of the correction process were used. The accuracy of the applied methods of the probe radius compensation process was estimated on the basis of the deviations calculated between corrected measurement points and scanning lines. The selection of scanning lines and the number of measurement points was realized by using the expert system based on the fuzzy logic. The paper presents the results of both simulation and experimental investigations. The numerical calculations were performed for two selected free-form surfaces. The verification of the developed algorithm was carried out during experimental investigations based on a measurement of a selected free-form surface. The conducted research was aimed at verifying the correctness of the distribution of measurement points generated using the proposed method. In the case of real measurements, measurement points should be located in the places of surfaces of products characterized by the largest deviations of manufacturing. The results of the conducted investigations confirm the usefulness of the developed algorithm for defining the distribution of measurement points on curvilinear surfaces in the coordinate measuring technique. Moreover, the way of implementation of the developed method of the distribution of measurement points in selected commercial measurement software is presented, thus enabling the use of the new method in the industry.

scholarly journals The accuracy of calculating form deviations of selected free-form surfaces

Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 1035-1037
Author(s):  
Marek Magdziak ◽  
Andrzej Kawalec
Keyword(s):  
Coordinate Measuring Machine ◽  
Measuring System ◽  
Free Form ◽  
Experimental Investigations ◽  
Simulation Studies ◽  
Numerical Investigations ◽  
Measuring Machine ◽  
Coordinate Measurements ◽  
Simulation Results ◽  
Free Form Surfaces

The possible reason for the incorrect form deviations calculated using an algorithm available in the selected software of coordinate measuring machine was identified. This method is available in the Calypso software and it is based on local deviations calculated at nominal points. The analysis was made for the selected examples of free-form surfaces. There are presented the results of numerical investigations based on simulations of coordinate measurements of selected object. The measured points were generated with assumed values of scatter in relation to the nominal profiles of the analyzed product. The simulations were made using 3 selected methods for computing the form deviations and various distances between the measured points. In order to verify the results of simulation studies there were made experimental investigations. The experimental investigations were done using selected coordinate measuring system and chosen measurement parameters. The results of performed measurements confirm the simulation results.

scholarly journals Selection of the Best Model of Distribution of Measurement Points in Contact Coordinate Measurements of Free-Form Surfaces of Products

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5346 ◽  
Author(s):  
Marek Magdziak
Keyword(s):  
Coordinate Measuring Machine ◽  
New Method ◽  
Free Form ◽  
Experimental Investigations ◽  
Accuracy Of Measurements ◽  
Measuring Machine ◽  
Coordinate Measurements ◽  
Free Form Surface ◽  
Free Form Surfaces ◽  
Selection Of

The article presents a new method for determining the distribution of measurement points, which can be used in the case of contact coordinate measurements of curvilinear surfaces of products. The developed method is based on multi-criteria decision analysis. In the case of the new method, the selection of the distribution of measurement points on free-form surfaces is carried out based on the analysis of five different criteria. The selection of the best model of the distribution of measurement points results from the accuracy of coordinate measurements, the time needed to complete measurement tasks, the number of measurement points, the accuracy of the substitute surface representing the measured free-form surface and the area where measurement points are located. The purpose of using the developed method of the distribution of measurement points is to increase the performance of coordinate measurements primarily by increasing the automation of strategy planning of measurements of curvilinear surfaces and improving the accuracy of measurements of free-form surfaces of products. The new method takes into account various aspects of coordinate measurements to determine the final model of the distribution of measurement points on measured surfaces of products, thereby increasing the probability of the proper determination (i.e., identifying the highest deviations of a product) of the location of measurement points on the surfaces of a measured object. The paper presents an example of the application of the created method, which concerns the selection of the best model of the distribution of measurement points on a selected free-form surface. This example is based on, among others, the results of experimental investigations, which were carried out by using the ACCURA II coordinate measuring machine equipped with the VAST XXT measuring probe and the Calypso measurement software. The results of investigations indicate a significant reduction in time of coordinate measurements of products when using the new method for determining the distribution of measurement points. However, shortening the time of coordinate measurements does not reduce their accuracy.

The influence of a number of points on results of measurements of a turbine blade

2017 ◽  
Vol 89 (6) ◽  
pp. 953-959 ◽  
Author(s):  
Marek Magdziak
Keyword(s):  
Turbine Blades ◽  
Measuring System ◽  
Free Form ◽  
Experimental Investigations ◽  
Content Type ◽  
Measurement Strategy ◽  
Accuracy Of Measurements ◽  
Uncertainty Of Measurements ◽  
Measuring Machine ◽  
Free Form Surfaces

Purpose The purpose of this paper was to determine the influence of a number of measured points on results of measurements of turbine blades, which are the parts of aircraft engines. The selection of a number of points is the part of a measurement strategy in the coordinate measuring technique and determines the accuracy of measurements. Design/methodology/approach Numerical and experimental investigations were conducted. The measurements were simulated using different numbers of measured points. The simulated measurements were performed for the selected dispersion of measured points. The dispersion reflected the inaccuracy of a manufacturing process of the considered product and the uncertainty of measurements of curvilinear surfaces. To verify the accuracy of the numerical studies, experimental research was conducted. The real measurements were conducted using the selected coordinate measuring machine. Findings The gained results following the simulations can be very useful when selecting the appropriate number of measured points. The chosen number of points may be used during real measurements of turbine blades conducted on coordinate measuring machines. The results of numerical research indicate that there should be used the average radii of leading and trailing edges to increase the accuracy of measurements. The results of real coordinate measurements confirmed the results of simulation studies. Originality/value The main novelty of the paper is the presented methodology for determining the influence of measured points on results of measurements. The presented methodology helps the user of a coordinate measuring system select the appropriate measurement strategy of free-form surfaces applied in the aerospace industry.

Research on Digital Modeling about Free-Form Surface with Holes Based on Coordinate Measuring Machine

2011 ◽  
Vol 287-290 ◽  
pp. 2805-2809
Author(s):  
Ming Yu Huang ◽  
Xiu Juan Wu ◽  
Zhong Shi Jia ◽  
Hong Jun Ni ◽  
Jing Jing Lv ◽  
...  
Keyword(s):  
Point Cloud ◽  
Coordinate Measuring Machine ◽  
Free Form ◽  
Model Reconstruction ◽  
Contact Measurement ◽  
Digital Modeling ◽  
Measuring Machine ◽  
Fast Reconstruction ◽  
Free Form Surface ◽  
Free Form Surfaces

Data acquisition and model reconstruction of free-form surfaces with holes were been studied, based on coordinate measuring machines. First, the structural process of the parts was analyzed, the method of combinate contact measurement with non-contact measurement were used to get point cloud; Then the point cloud were been preprocessed, feature curve extracted and solid modeled; Finally, the restructure model was been quality assessed and accuracy assessed. Using the measurement of combinated contact and non-contact can also meet both the precision requirement of key part and the fast reconstruction requirement of non-critical part, which has great significance on that part to fast and accurate reconstruction.

Comparison of GA, ACO algorithm, and PSO algorithm for path optimization on free-form surfaces using coordinate measuring machines

2021 ◽  
Author(s):  
Yueping Chen ◽  
Naiqi Shang
Keyword(s):  
Optimization Algorithm ◽  
Ant Colony Algorithm ◽  
Ant Colony ◽  
Path Optimization ◽  
Inspection Time ◽  
Free Form ◽  
Coordinate Measuring Machines ◽  
Ant Colony Optimization Algorithm ◽  
Measuring Machine ◽  
Free Form Surfaces

Abstract Coordinate measuring machines (CMMs) play an important role in modern manufacturing and inspection technologies. However, the inspection process of a CMM is recognized as time-consuming work. The low efficiency of coordinate measuring machines has given rise to new inspection strategies and methods, including path optimization. This study describes the optimization of an inspection path on free-form surfaces using three different algorithms: an ant colony optimization algorithm, a genetic algorithm, and a particle swarm optimization algorithm. The optimized sequence of sampling points is obtained in MATLAB R2020b software and tested on a Leitz Reference HP Bridge Type Coordinate Measuring Machine produced by HEXAGON. This study compares the performance of the three algorithms in theoretical and practical conditions. The results demonstrate that the use of the three algorithms can result in a collision-free path being found automatically and reduce the inspection time. However, owing to the different optimization methodologies, the optimized processes and optimized times of the three algorithms, as well as the optimized paths, are different. The results indicate that the ant colony algorithm has better performance for the path optimization of free-form surfaces.

scholarly journals A new method for choosing between ball-end cutter and toroidal cutter when machining free-form surfaces

2020 ◽  
Vol 111 (5-6) ◽  
pp. 1425-1443
Author(s):  
Mahfoud Herraz ◽  
Jean-Max Redonnet ◽  
Marcel Mongeau ◽  
Mohammed Sbihi
Keyword(s):  
New Method ◽  
Free Form ◽  
Free Form Surfaces ◽  
Toroidal Cutter

Assessment of Free-Form Surfaces’ Reconstruction Accuracy

2017 ◽  
Vol 24 (2) ◽  
pp. 303-312 ◽  
Author(s):  
Artur Wójcik ◽  
Magdalena Niemczewska-Wójcik ◽  
Jerzy Sładek
Keyword(s):  
Accuracy Assessment ◽  
Coordinate Measuring Machine ◽  
System Structure ◽  
Free Form ◽  
Correction Algorithm ◽  
Reconstruction Accuracy ◽  
Machining Center ◽  
Cad Cam ◽  
Measuring Machine ◽  
Free Form Surfaces

AbstractThe paper presents the problem of assessing the accuracy of reconstructing free-form surfaces in the CMM/CAD/CAM/CNC systems. The system structure comprises a coordinate measuring machine (CMM) PMM 12106 equipped with a contact scanning probe, a 3-axis Arrow 500 Vertical Machining Center, QUINDOS software and Catia software. For the purpose of surface digitalization, a radius correction algorithm was developed. The surface reconstructing errors for the presented system were assessed and analysed with respect to offset points. The accuracy assessment exhibit error values in the reconstruction of a free-form surface in a range of ± 0.02 mm, which, as it is shown by the analysis, result from a systematic error.

scholarly journals Improving the accuracy of free-form surface machining on CNC milling machines

Mechanik ◽  
2018 ◽  
Vol 91 (12) ◽  
pp. 1100-1103
Author(s):  
Andrzej Werner
Keyword(s):  
Geometric Model ◽  
Free Form ◽  
Cnc Milling ◽  
Surface Machining ◽  
Machining Errors ◽  
Milling Machines ◽  
Coordinate Measurements ◽  
Free Form Surface ◽  
Free Form Surfaces

This article presents a method of increasing the accuracy of the production of free-form surfaces. This method is based on the execution of coordinate measurements of the pre-treated object and reconstruction of its nominal geometric model in order to compensate existing machining errors.

Touch probe radius compensation for coordinate measurement using kriging interpolation

1997 ◽  
Vol 211 (1) ◽  
pp. 11-18 ◽  
Author(s):  
J. R. R. Mayer ◽  
Y. A. Mir ◽  
F Trochu ◽  
A Vafaeesefat ◽  
M Balazinski
Keyword(s):  
Computer Aided Design ◽  
Kriging Interpolation ◽  
Free Form ◽  
Probe Radius ◽  
Part Surface ◽  
Probe Radius Compensation ◽  
Normal Vectors ◽  
Radius Compensation ◽  
Free Form Surfaces ◽  
Touch Probe

Obtaining CAD (computer aided design) descriptions of actual parts having complex surfaces is a key part of the process of reverse engineering. This paper is concerned with the estimation of actual surfaces using coordinate measuring machines fitted with a spherically tipped touch probe. In particular, it addresses in detail the problem of probe radius compensation. A general mathematical model, using kriging, is proposed which first generates the initial probe centre surface and then estimates the compensated or part surface. The compensation is achieved using normal vectors to the initial probe centre surface at each measured point to compensate for the probe radius. The method is validated experimentally on known and free-form surfaces.

Tool Path Generation for Machining Shrouded Turbine Blisk

2004 ◽  
Author(s):  
Xiang Wu ◽  
Wansheng Zhao ◽  
R. Du
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
New Method ◽  
Free Form ◽  
Machining Accuracy ◽  
Geometrical Shape ◽  
Path Generation ◽  
Simultaneous Control ◽  
Turbine Blisk ◽  
Free Form Surfaces

Shrouded turbine blisk is an important component for liquid-propellant rocket engine, airplane engine and some other high-power turbine machines. It is made from high-temperature alloy (e.g., nickel-base alloy and titanium alloy) and hence, is difficult to machine. In addition, its geometrical shape is complicated involving many semi-enclosed, twisted, free-form surfaces. In order to ensure the best performance, its dimension accuracy is very demanding. For the moment, an effective way to manufacture shrouded turbine blisk is Electrical Discharge Machining (EDM) using form tools (form electrodes). However, owing to its complicated geometry, existing commercial CAM systems cannot generate the interference-free tool path for it. In this paper, a new tool path generation method is presented. The new method is base on the quadratic programming and CNC multi-axis simultaneous control. It generates tool path in two steps. First, a feasible zone is generated by coarse search, which gives an elementary path for form tool feed. Then, within the feasible zone the actual NC tool path is found by fine search through CNC multi-axis simultaneous control simulation. In practice, a form tool follows the interference-free tool path moving into the twisted passages of blisk for machining, while the blisk is turning by a CNC turntable. The new method is validated experimentally. Compared to the existing methods, it can obtain high machining efficiency and high machining accuracy. Experimental results indicate that the new method is accurate. This new method can also be applied to many other machining applications involving complicated geometrical shape.

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