Papers by Keyword: Flatness Error

Abstract: Optimization of a flatness error inspection activity on coordinate measuring machine (CMM) is a very crucial problem which demands minimization of a probe path for productive inspection. In the present work, the approach is explained to minimize the total probe travelling length and hence, the time of flatness inspection. Three sampling methods with eight sample sizes have been considered for this work. The ant colony optimization (ACO) algorithm based on travelling salesman problem (TSP) approach was developed in MATLAB environment to find the shortest probe paths. It was verified that the probe path depends on the sampling method used to measure the flatness. The sampling method giving the shortest probe path was selected as the best-suited method for a particular sample size. The results obtained by analyzing an illustrative example shows that the proposed approach is both effective and optimum.

Abstract: The work described in this paper pertains to the identification of some features of micro- and macroprofile formation of surfaces to be machined with flat face grinding, with inclination of the spindle axis. The question of the formation of machined surface profile at through-feed grinding and multiple-pass scheme are considered by using computer-aided simulations in COMPASS environment. More specifically, for flat face through-feed grinding, a generalized empirical equation exhibiting the dependency of concavity from the outer diameter of the face grinding wheel, the spindle axis inclination angle and the width of the surface of the workpiece is acquired. Furthermore, based on the maximum allowable value of flatness deviation and with pre-determined grinding wheel diameter and workpiece width, it is possible to identify the maximum inclination angle at which concavity falls within acceptable limits. For the case of multiple pass flat face grinding, the role of factors such as inclination angle of spindle axis, cross-feed and diameter of the grinding wheel on the height of residual ridges on the surface of the parts is determined through the proposal of an empirical equation. With the aforementioned equations the machinist may reasonably prescribe machining conditions in practice. The conducted research contributes to the expansion of ideas regarding technological possibilities of improvement of flat face grinding.

Abstract: To effectively realize fast and high accurate measurements of flatness error on the surface of machining workpiece, multiple sets of actual machining experimental data are used as samples, a soft-sensing model of flatness error on the surface of machining workpiece is established by using the speed n, the moving speed of carriage uy and the voltage U of piezoelectric ceramic micro-feed drive as arguments with SVM(Support Vector Machine), and adaptive genetic algorithm is used to optimize the allowable error ε, the number of positive gasification rules c and the parameters of kernel function r, the results of training, testing and practical application show, after the optimization of 200 steps, training mean relative error which became saturated is 3.4%, testing relative error is less than 2.6%, the range of average relative error between the soft measurement value of flatness error on the surface of machining workpiece and the test value of L-730 laser flatness measuring instrument is 1.2% to 2.4%.

Abstract: Improving the machining precision mechanical manufacturing field is an indispensable chapter topic. In this analysis focuses on the rail straightness, process system stiffness, milling way, cutting layer parameters, tool wear, thermal deformation of the workpiece spindle axis traverse peace pliers jaws of irregularities in the machining precision flatness influence. Milling cutting process parameters of different layers, different milling heat, different deformation of the workpiece, resulting flatness error is different. Different milling methods and different milling force also affect flatness errors. Therefore, the workpiece machining pass these factors need to be considered. And proposed a solution for uneven of flat-nose pliers jaws and surface of workpiece.

Abstract: The automatic measuring instrument for the flatness error of the rail wagon is designed with carbon fiber and aluminium alloy, which makes the instrument handy with good stiffness. After the design for the main structure and arranging the position of sensing element, finite element analysis is used to guarantee that deformation of structure itself will not affect the measurement accuracy. The design of the automatic measuring instrument for the flatness error of the Rail wagon takes the place of tradional feeler gauge measurement, raised the work efficiency and improves the measurement accuracy to 0.1mm.

Abstract: Matlab and Microsoft Visual C++ were used to program the automatic measuring instrument for the flatness error of the Rail wagon. Microsoft Visual C++ is used to program the struct body, which takes full advantage of the high programming efficiency, high execution speed and beautiful imple interface. In the meantime, powerful computational function and image fitting of Matlab is added to the program. Through the method of Dynamic Link Library, these two softwares are linked and the figure created by Matlab can be insetted in the main interface created by Microsoft Visual C++, which keeps the united and elegant appearance.

Abstract: Measurement of geometrical tolerances is one of the prime processes in manufacturing for ensuring the quality of the machined components. Manufactured components are sent to assembly line based on measurement reports, so measurement is inevitable in any production setup. Flatness error is one of the important icons in the crew of geometrical tolerances; if unqualified components are sent to assembly line, the components may not function according to the design requirements. This paper presents real coded efficient genetic algorithms (EGA) for flatness error measurement and flatness plane development using minimum zone method. Flatness plane has been developed by determining the flatness plane coefficients. The flatness plane coefficients determine the orientation of the surface. The proposed algorithms are equipped with high precision, accuracy, good repeatability and fast mature convergence rate. The algorithms characteristics like precision, accuracy, repeatability ensure the reliability of measurement results of measured component and fast mature convergence rate ensure the reduction in the inspection time.

Abstract: Measurement of parallelism error is one of important icon in the measurement of orientation tolerances. This paper presents new method of parallelism error measurement and is based on the flatness plane using minimum zone technique. Real coded genetic algorithm has been proposed to determine the flatness plane coefficients and flatness error. Flatness plane has been developed using plane coefficients and then parallelism error has been determined from the flatness plane. One example has been presented to show the effectiveness of the proposed parallelism error measurement method. The result of the proposed method has been compared to co-ordinate measuring machine (CMM) built-in function for parallelism error measurement and the results are in good agreement. In addition to determination of parallelism error measurement, the proposed algorithms also calculate flatness error and can also be extended to measurement of other types of geometrical tolerances with slight modifications.

Abstract: A new flatness error measurement method was proposed for large quantities of E-type AC relay, which was consisted of three discontinuous plane. The research object of this thesis is on both sides of the work piece plane. The relay was measured by utilizing multiple laser displacement sensors, and used the development of PC software to extract the measurement key points and process the collected data, which was used the method of least squares to calculate more accurate flatness error value. This method can achieve substandard work-piece fast sorting and rapid online measure.

Abstract: A new method for extracting spectrum feature of gas flucturation of aerostatic guideway is proposed. The flatness error of workpiece surface includes much errors information, and the information contains high frequency signal and low frequency signal, for these errors information, a new identification method of turning errors of workpiece based on the wavelet transform and power spectral density analysis is proposed. According to the focal variation character of wavelet and the energy value of power spectral density analysis, the feature of gas flucturation of aerostatic guideway from the measured flatness error of workpiece is extracted and identified.