Real-time Compensation for Time-variant Volumetric Errors on a Machining Center

1993 ◽  
Vol 115 (4) ◽  
pp. 472-479 ◽  
Author(s):  
J. S. Chen ◽  
J. X. Yuan ◽  
J. Ni ◽  
S. M. Wu
Keyword(s):  
Real Time ◽  
Computer Control ◽  
Thermal Error ◽  
Coordinate Measuring Machine ◽  
Error Components ◽  
Machine Errors ◽  
Machining Center ◽  
Volumetric Errors ◽  
Measuring Machine ◽  
Cnc Controller

An error compensation system has been developed to enhance the time-variant volumetric accuracy of a 3-axis machining center by correcting the existing machine errors through sensing, metrology, and computer control techniques. A general methodology has been developed to synthesize both the geometric and thermal errors of machines into a time-variant volumetric error model. Instead of the well-known 21 geometric error components, 32 machine linkage errors are formulated as a 4D error field including the space domain and the time domain. Different types of models are proposed for different kinds of thermal error components. A compensation controller based on an IBM/PC has been linked with a CNC controller to compensate for machine errors in real time. This scheme has been implemented on a horizontal machining center and has been shown, using metrology instruments, to improve the machine accuracy by an order of magnitude. A cut workpiece inspected using a coordinate measuring machine (CMM) has also shown that dimension errors have been reduced from 92.4 μm to 18.9 μm in a dimension of 404 × 310 mm2 and the depth difference of milled surfaces has been reduced from 196 μm to 8 μm.

Routine Monitoring DCC CMM using Laser Interferometer

2019 ◽  
Vol 5 (1) ◽  
pp. 7-14
Author(s):  
Paulus Agung Krismantara
Keyword(s):  
Laser Interferometer ◽  
Computer Control ◽  
Coordinate Measuring Machine ◽  
Critical Factor ◽  
Machine Error ◽  
Machine Age ◽  
Machine Errors ◽  
Routine Monitoring ◽  
Measuring Machine ◽  
Consistent Performance

Manufacturing deals with the high quality product due to the accuracy which produced by measuring machines. In other case, the performance of regular diagnostic of measuring machine should be maintained to aim confidence and reliability in the measurements result. One of the equipment that can reach high accuracy is Direct Computer Control Coordinate Measuring Machine (DCC CMM). The accuracy of DCC CMM is a critical factor that affects result of product measuring. Operator need the higher accuracy machine to maintain the DCC CMM Performance and the consequent of the machine should has better accuracy than the DCC CMM accuracy it self. One of that tool is laser interferometer which has better accuracy than DCC CMM specification and produce the data and can be analyzed for DCC CMM performance. The consistent performance of the DCC CMM is constrained by the errors that brought by the machine error that occurs on a periodic basis on the account of machine usage, machine age and operating temperature. DCC CMM accuracy was compensated and improved by identifying the machine condition. This condition also applicable for predict the machine errors.

Research on S-gear design, manufacturing and measuring based on NC machining center

2020 ◽  
pp. 095440542098134
Author(s):  
Shao-ying Ren ◽  
Yan-zhong Wang ◽  
Yuan Li
Keyword(s):  
Convex Surface ◽  
Coordinate Measuring Machine ◽  
Nc Machining ◽  
Tooth Profile ◽  
Numerical Control ◽  
Machining Center ◽  
Involute Gear ◽  
Measuring Machine ◽  
Gear Contact ◽  
Nc Machining Center

This article presents a method of design, manufacturing, and measuring S-gear. S-gear is a kind of gear whose tooth profile is an S-shaped curve. The sine (cosine) gear, cycloid gear, polynomial gear, and circular arc gear are all S-gears in essence. In the S-gear transmission, the concave surface of one gear and the convex surface of the other gear contact each other. Therefore, the power transmitted by S-gear is much larger than that of the convex-convex-contact involute gear. Some scholars have studied the characteristics of S-gear, but few have explored its manufacturing. In this article, the Numerical Control (NC) machining technology of S-gear is studied in detail for its industrial application. The polynomial curve is used to construct the tooth profile of the S-gear based on the Gear Meshing Theory. The mathematical model of polynomial S-gear is established, by which involute gear can be represented as a special S-gear. The steps of generating NC codes are described. Then, the S-gear sample is processed with an NC machining center. Finally, the sample is measured with a Coordinate Measuring Machine (CMM), and the measurement results show that the accuracy of the S-gear processed by the NC machining center reaches ISO6. This research provides a feasible approach for the design, manufacturing, and measuring of S-gear.

Experiment Study on Deflection of Aluminum Alloy Thin-Wall Workpiece in Milling Process

2011 ◽  
Vol 697-698 ◽  
pp. 129-132 ◽  
Author(s):  
Bing Han ◽  
Cheng Zu Ren ◽  
X.Y. Yang ◽  
Guang Chen
Keyword(s):  
Aluminum Alloy ◽  
Coordinate Measuring Machine ◽  
Milling Process ◽  
Cnc Machining ◽  
Machining Accuracy ◽  
Thin Wall ◽  
Machining Center ◽  
Machining Errors ◽  
Alloy Material ◽  
Measuring Machine

The deflection of Aluminum alloy thin-wall workpiece caused by the milling force leads to additional machining errors and reduces machining accuracy. In this paper, a set of experiments of milling thin-wall workpiece were carried out to study the deflection of thin-wall workpiece. The workpieces, with different types of material and different thicknesses, were machined on CNC machining center. The deflections of workpiece were measured by a three-coordinate measuring machine. Effects of Aluminum alloy material and thickness on deflection are discussed based on the experimental data.

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.

Layer Based Robot Machining for Rapid Prototyping

2000 ◽  
Author(s):  
Y. Song ◽  
Y. H. Chen
Keyword(s):  
Rapid Prototyping ◽  
Large Scale ◽  
Tool Path ◽  
Coordinate Measuring Machine ◽  
Cnc Machining ◽  
Stl File ◽  
Machining Center ◽  
Machining System ◽  
Robot Machining ◽  
Measuring Machine

Abstract Many useful methods have been applied to Rapid Prototyping (RP) technologies in recent years, and each of them has its own features. To solve the problem in large-scale prototyping, a robotic machining center with layer based algorithms is developed. Using STereoLithography (STL) file, the surfaces of a model are represented by triangles. Calculating the intersection between a series of parallel planes and the STL file, a STereolithography Contour (SLC) file of the model is generated where the model is represented as a series of contours on a set of parallel planes. Instead of using the popular RP technologies, traditional Computer Numerical Controlled (CNC) machining method is applied in machining each layer of the model. With visibility calculation, the thickness of each material layer is selected. When collision is detected for a point on the tool path, the orientation of the tool is modified. With the machining of a vase model, the effectiveness of the proposed algorithm is demonstrated. Errors of the robot machining system are analyzed by a Coordinate Measuring Machine (CMM) and a surface texture measuring machine.

Thermal Error Compensation on Boring & Milling Machining Center Feed System Based on PMAC

2014 ◽  
Vol 945-949 ◽  
pp. 1669-1672
Author(s):  
Jun Sun ◽  
Xing Liu ◽  
Zhi Xuan Li
Keyword(s):  
Real Time ◽  
Error Compensation ◽  
Tool Path ◽  
Thermal Error ◽  
Machining Accuracy ◽  
Feed System ◽  
Nc Machine Tool ◽  
Machining Center ◽  
Nc Machine ◽  
Processing Accuracy

Aiming to deal with thermal error of NC machine tool which can cause reduce of machining accuracy, this paper uses an external error compensation which interacts with NC controllers and PMAC multi-axis and then revises the tool path by adding the error tested in real-time by PMAC card. The processing accuracy is improved eventually. This method can compensate machine geometric errors and thermal errors in real-time. Comparing with other methods of error preventing, this method is more effective and affordable.

Comparative Statistical Analysis of Test Parts Manufactured in Production Environments

2004 ◽  
Vol 126 (1) ◽  
pp. 189-199 ◽  
Author(s):  
David E. Gilsinn ◽  
Alice V. Ling
Keyword(s):  
Statistical Analysis ◽  
Machine Tool ◽  
Coordinate Measuring Machine ◽  
Hole Center ◽  
Machining Center ◽  
Production Environments ◽  
Measuring Machine ◽  
Comparative Statistical Analysis ◽  
Uncertainty Models ◽  
Propagation Of Uncertainties

Estimating error uncertainties arising in production parts is not a well-understood process. An approach to estimate these uncertainties was developed in this study. Machine tool error components were measured on a three-axis vertical machining center. Multiple parts were produced on the measured machining center then measured on a coordinate measuring machine. Uncertainty models for hole-center to hole-center lengths and orthogonalities were developed using measured machine tool errors. These estimated uncertainties were compared against measured uncertainties. The main conclusion from the study is that the Law of Propagation of Uncertainties can be used to estimate machining uncertainties.

Calibration of Positional Errors in Coordinate Measuring Machines and Machine Tools Using a Laser Interferometer System

2015 ◽  
Vol 798 ◽  
pp. 303-307 ◽  
Author(s):  
Benedito di Giacomo ◽  
César Augusto Galvão de Morais
Keyword(s):  
Machine Tools ◽  
Coordinate Measuring Machine ◽  
Laser Interferometry ◽  
Dynamic Mode ◽  
Coordinate Measuring Machines ◽  
Measurement Systems ◽  
Volumetric Errors ◽  
Bridge Type ◽  
Measuring Machine

Dimensional inspections in manufactured workpieces allow assess the quality of the manufacturing process, in this context the quality and development of measurement systems are issues addressed by many researchers. The coordinate measuring machines (CMMs) are versatile systems, can measure complex geometries quickly and accurately. Positional errors are parts of volumetric error and affect the correct positioning of probe in CMMs or of the tool in machine tools. Faced with this, the purpose this investigation is show a method to calibrate the positional errors in a bridge-type coordinate measuring machine, this method collects data in dynamic mode and reduces cyclic errors. The calibration of positional errors was performed using laser interferometry in the “on-the-fly” mode and a method to reduce cyclic errors was applied. The highest value of position error occurred in x axis with value positive of 10μm in the position of 220mm, while in the y and z axis the higher absolute values were 2μm and 6μm respectively. From calibration and compensating of positional errors it is possible to reduce the effects of the volumetric errors in machines with axis of linear displacements as the CMMs and machine tools.

Synthesis Error Modeling and Thermal Error Compensation of Five-Axis Machining Center

2006 ◽  
Vol 532-533 ◽  
pp. 49-52 ◽  
Author(s):  
Xiu Shan Wang ◽  
Jian Guo Yang ◽  
Qian Jian Guo
Keyword(s):  
Real Time ◽  
Error Compensation ◽  
Thermal Error ◽  
Error Model ◽  
Error Modeling ◽  
Thermal Displacement ◽  
Collector System ◽  
Machining Center ◽  
Five Axis ◽  
Thermal Error Compensation

The synthesis error model of UCP710 five-axis machining center is divided into two parts: the position and orientation error models, and the article gets their models which are used as real-time compensation. One data collector system of thermal displacement and temperature is developed and used as real-time compensation for UCP710. The results of thermal error compensation have proved that the error model is correct and collector system works well.

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