• Title/Summary/Keyword: Surface Error Compensation

Search Result 70, Processing Time 0.033 seconds

An Error Compensation in Rough Surface Measurement by Contact Stylus Profilometer (표면미세형상측정을 위한 접촉식 형상측정기의 오차 보정)

  • 조남규
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.8 no.1
    • /
    • pp.126-134
    • /
    • 1999
  • In this paper, a new error compensating technique for form-error compensation of rough-surface profile obtained by contact stylus profilometer is proposed. By the method, the real contact points of rough-surface and diamond stylus can be estimated and the measured profile data corrected. To verify the compensation effect, the properties(Ra, RMS, Kurtosis, Skewness) of measured profile data and compensated data were compared. And, the cumulative RMS slope was proposed to assess the compensated effect of upper area of profile. The results show that the measuring error could be compensated very well in amplitude parameters and in proposed cumulative RMS slope by the developed form-error compensating technique.

  • PDF

A Measurement Method to Compromise Surface Error in Machined Workpieces (평면 오차 보정 가공을 위한 측정 방법에 관한 연구)

  • 장문주;홍성욱;박천홍
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2002.05a
    • /
    • pp.409-412
    • /
    • 2002
  • This paper presents a measurement method to compromise surface error in surface machining processes. In order to compromise the surface error in machining process, on-machine measurement is essential. There are two kinds of on-machine measurement methods available to measure the surface errors in flat workpieces: i.e., surface scanning method and sensor scanning method. However, motion errors are inevitably engaged in both methods. This paper proposes a new idea to measure the surface error for error compensation. The measurement system consists of a laser, a CCD camera and processing system, a carrier system with a stylus, and some optical units. The experimental results show that the proposed method is useful to compensate the surface errors of machined workpieces.

  • PDF

Study of Machined Surface Error Compensation for Autonomous Manufacturing System (자율가공 시스템을 위한 가공면 오차보상에 관한 연구)

  • 서태일
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.9 no.4
    • /
    • pp.75-84
    • /
    • 2000
  • The main goal of our research is to compensate the milled surface errors induced by the tool deflection effects, which occur during the milling process. First, we predict cutting forces and tool deflection amount. Based on predicted deflection effects, we model milled surface shapes. We present a compensation methodology , which can generate a new tool trajectory, which is determined so as to compensate the milled surface errors. By considering manufacturing tolerance, tool path compensation is generalized. To validate the approaches proposed in this paper, we treat an illustrative example of profile milling process by using flat end mill. Simulation and experimental results are shown.

  • PDF

Autofocus system for off-line focusing error compensation in micro laser fabrication process (레이저 미세가공용 자동초점장치를 이용한 오프라인 초점 오차 보상에 관한 연구)

  • Kim, Sang-In;Kim, Ho-Sang
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.26 no.6
    • /
    • pp.50-58
    • /
    • 2009
  • Micro laser fabrication techniques can potentially be used for the manufacture of microstructures on the thin flat surfaces with large diameter that are frequently used in semiconductor industries. However, the large size of wafers can cause the degraded machining accuracy of the surface because it can be tilted or distorted by geometric errors of machines or the holding fixtures, etc. To overcome these errors the off-line focusing error compensation method is proposed. By using confocal autofocus system, the focusing error profile of machined surface is measured along the pre-determined path and can be compensated at the next machining process by making the corrected motion trajectories. The experimental results for silicon wafers and invar flat surfaces show that the proposed method can compensate the focusing error within the level of below $6.9{\mu}m$ that is the depth of focus required for the laser micromachining process.

Development of Optical Fiber Coupled Displacement Probe Sensor with a New Compensation Method (보상법을 적용한 광섬유 변위센서의 개발)

  • ;;;P. Sainsot;L. Flamand
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.19 no.12
    • /
    • pp.27-32
    • /
    • 2002
  • The intensity modulated type (reflective method) optical fiber sensor is a well -known method and widely applied to the displacement measurements and other industrial purposes. This type sensor has the advantages of relatively cheap cost, small sensor size and easiness of operation. The sensitivity of the sensor is very dependent of several error terms; the variation in the intensity of the light source and the changes in the surface reflectivity of the object. An optical fiber coupled displacement probe with a new compensation method is presented in this paper. The proposed displacement sensor can measure the displacements of the target surface independent of surface reflectivity error that is caused by the materials and surface processing grade.

On-line Tool Deflection Compensation System for Precision End-milling (정밀 엔드밀링을 위한 실시간 공구처짐 보정시스템)

  • Yang, Min-Yang;Choe, Jong-Geun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.21 no.2
    • /
    • pp.189-198
    • /
    • 1997
  • This paper presents development of a practical tool deflection compensation system in order to reduce the machining error from the tool deflection compensation system in order to reduce the machining error from the tool deflection in the end-milling process. The devised system is a tool adapter which includes 1-axes force sensor for detecting tool deflection and 2-axes tool tilting device for adjusting tool position through computer interface on line process. Experimental in investigations for typical shaped workpieces representing various end milling situations are performed to verify the ability of the system to suppress the surface errors due to tool deflections. With the system, it is possible to get precise machining surface without any excessive machining error due to increased cutting force in more productive machining conditions.

Disturbance Observer-based Current Measurement Offset Error Compensation in Vector-controlled SPMSM Drives (표면 부착형 동기 전동기 벡터 제어에서의 외란 관측기 기반 전류 측정 오프셋 오차 보상 방법)

  • Lee, Sang-Min;Lee, Kibok
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.27 no.5
    • /
    • pp.402-409
    • /
    • 2022
  • In vector-controlled drive systems, the current measurement offset error causes unwanted torque ripple, resulting in speed and torque control performance degradation. The current measurement offset error is caused by various factors, including thermal drift. This study proposes a simple DC offset error compensation method for a surface permanent magnet motor based on a disturbance observer. The disturbance observer is designed in the stationary reference frame. The proposed method uses only the measured current and machine parameters without additional hardware. The effect of parameter variations is analyzed, and the performance of the current measurement offset error compensation method is validated using simulation and experimental results.

Error Compensation Algorithm for Higher Surface Accuracy of Freeform Mirrors Based On the Method of Least Squares

  • Jeong, Byeongjoon;Pak, Soojong;Kim, Sanghyuk;Lee, Kwang Jo;Chang, Seunghyuk;Kim, Geon Hee;Hyun, Sangwon;Jeon, Min Woo
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.40 no.2
    • /
    • pp.40.1-40.1
    • /
    • 2015
  • Off-axis reflective optical systems have attractive advantages relative to their on-axis or refractive counterparts, for example, zero chromatic aberration, no obstruction, and a wide field of view. For the efficient operation of off-axis reflective system, the surface accuracy of freeform mirrors should be higher than the order of wavelengths at which the reflective optical systems operate. Especially for applications in shorter wavelength regions, such as visible and ultraviolet, higher surface accuracy of freeform mirrors is required to minimize the light scattering. In this work, we propose the error compensation algorithm (ECA) for the correction of wavefront errors on freeform mirrors. The ECA converts a form error pattern into polynomial expression by fitting a least square method. The error pattern is measured by using an ultra-high accurate 3-D profilometer (UA3P, Panasonic Corp.). The measured data are fitted by two fitting models: Sag (Delta Z) data model and form (Z) data model. To evaluate fitting accuracy of these models, we compared the fitted error patterns with the measured error pattern.

  • PDF

Numerical and Experimental Study for Improvement of Formability in Flexible Forming Process (가변성형공정에서 성형성 향상을 위한 해석 및 실험적 연구)

  • Heo, S.C.;Seo, Y.H.;Kang, B.S.;Kim, J.
    • Transactions of Materials Processing
    • /
    • v.21 no.7
    • /
    • pp.432-440
    • /
    • 2012
  • In this article, the design of the flexible forming process considering die shape compensation using an iterative over-bending method based on numerical simulation was conducted. In this method, the springback shape obtained from the final step of the first forming simulation is compared with the desired objective shape, and a shape error is calculated as a vector norm with three-dimensional coordinates. The error vector is inversely added to the objective surface to compensate both the upper and lower flexible die configurations. The flexible die shapes are recalculated and the punch arrays are adjusted according to the over-bent forming surface. These iterative procedures are repeated until the shape error variation converges to a small value. In addition, experimental verification was conducted using a 2000-kN flexible forming apparatus for thick plates. Finally, the configuration of the prototype obtained from the experiment was compared with the numerical simulation results, which had springback compensation. It is confirmed that the proposed method for compensating for the forming error could be used in the design of flexible forming of thick-curved plates.

Method for tool alignment error Compensation of Angle controlled Ultra-Precision machining (각도 제어 초정밀 가공기의 공구 위치 검출)

  • Park, Soon-Sub;Lee, Ki-Young;Kim, Hyoung-Mo;Lee, Jae-Seol
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.6 no.3
    • /
    • pp.53-57
    • /
    • 2007
  • This paper presents a geometrical error compensation of tool alignment for B axis controlled machine. In precision machining, tool alignment is crucial parameter for machined surface. To decrease tool alignment error, plus tilted tool from B axis center is touched to reference work piece and checked the deviation from original position. Same process is performed in minus tilt. Comparing these 2 touch positions, wheel alignment error in X axis and Z axis can be calculated on B axis center. Experimental results show that this compensation method is efficient to correct tool alignment.

  • PDF