공작기계의 동특성에 의한 Chatter 진동의 해석

朴重潤 金烏工科大學校 1985 論文集 Vol.6 No.-

In This study, an analysis of chatter vibration due to vibration mode coupling of structure is considered. Chatter vibration is effected by dynamics of machine tool structure. Dynamics of structure modeled by 2 degree of freedom are functions of principal direction angle of vibration mode and the ratio each natural frequency. The maximum width of cut for chatter free condition is calculated. The variation of the principal directional angle of mode is very critical in the range of resultant cutting force direction.

입자 구형도에 따른 레이저 선가공의 비구형 흄 마이크로 입자 산포 특성 연구

박중윤,김경진 한국반도체디스플레이기술학회 2022 반도체디스플레이기술학회지 Vol.21 No.2

This computational investigation of micro-sized particle dispersion concerns the fume particle contamination over target surface in high-precision laser line machining process of semiconductor and display device materials. Employing the random sampling based on probabilistic fume particle generation distributions, the effects of sphericity for nonspherical fume particles are analyzed for the fume particle dispersion and contamination near the laser machining line. The drag coefficient correlation for nonspherical particles in a low Reynolds number regime is selected and utilized for particle trajectory simulations after drag model validation. When compared to the corresponding results by the assumption of spherical fume particles, the sphericity of nonspherical fume particles show much less dispersion and contamination characteristics and it also significantly affects the particle removal rate in a suction air flow patterns.

권두언

박중윤 대한지방행정공제회 1975 도시문제 Vol.10 No.7

N/A

復合再生效果에 의한 自勵振動에 관한 硏究

朴重潤 金烏工科大學校 1987 論文集 Vol.8 No.-

A new method for analysis of chatter vibration is presented. It is shown that vibrating energy of the multiple regenerative chatter is maximized when chatter is fully developed. It is assumed that chatter frequency is constant, and motion has finite limit amplitude. Thus, linear analysis is possible by taking the Fourier Series expansion for nonlinear cutting force. In this paper, chatter frequency is varied to maximize the vibrating energy, and chatter amplitude in this condition is also computed. The results of this method is compared with that of direct numerical integration method. The results obtained by each method are good agreements when chatter amplitude has finite limit cycle. This method is useful for one degree of freedom system because of assumption.

공구의 처짐을 고려한 복합 자려진동에 대한 연구

박중윤 金烏工科大學校 1990 論文集 Vol.11 No.-

The multiple regenerative chatter vibration due to the deflection of tool occurring in orthogonal cutting is investigated. Tool deflection is a bad chatter condition and causes severe chatter. General chatter generates the constant chatter amplitude, but severe chatter due to small tool deflection has varying chatter amplitude and chatter frequency. It is shown that the severe chatter with large tool deflection, the larger chatter amplitude, but the chatter amplitude and chatter frequency are kept constant.

동흡진기를 이용한 진동 제어에 관한 연구

박중윤 國立金烏工科大學校附設生産技術硏究所 1991 産業技術開發硏究 Vol.7 No.-

This paper presents and analysis of the vibration system with a dynamic absorber. The purpose of this paper is to suggest one of directives to design passive and active dynamic absorbers. If the exciting frequency of the exciting force is harmonic(or constrant), the passive absorber is effective. In this case, optimal tuned absorber suppresses the vibration of the main system. On the contrary, the mistuned absorber promotes the vibration. Thus, vibration amplitude for design variables of the absorber is investigated. In random or irregular exciting force, the active absorber is more effective. In this case, the control law is used as optimal regulator theory. Design variables of weighting matrix and feedback gain vector are considered, and an optimal design chart can be obtained from this design variables. It is demonstrated that this method is effective for the design of an active vibration absorber.

자기-공기 서스펜션기구의 동특성 해석

小野京右,박중윤 金烏工科大學校 1997 論文集 Vol.18 No.-

This paper studied the dynamic characteristics of a magnetic-air suspension mechanism. The motive of this study is to stabilize the air bearing system with disturbances. The vibration system consists of a air cylinder with orifice and permanent magnets. When the basement is excited by disturbances, the transmitted vibration of the cylinder is effected by the magnetic force, air flow, and air cushion of the chamber. The dynamic equations of the system are formulated. The experimental works are performed with the variation of masses of the cylinder, clearances, and lengthes of the piston, and the results show good agreement with those of numerical simulations in a linear region. A few nonlinear phenomena are submitted.

부분적으로 일정한 자기장의 영향을 받는 보의 동적해석에 관한 연구

홍성욱,박중윤 金烏工科大學校 1992 論文集 Vol.13 No.-

This paper presents the dynamic analysis of a beam subjected to a piecewise uniform magnetic field. The objective of this study is to test the applicability of a passive magnetic damper in the suppression of structural vibration. The fundamental idea of the passive magnetic damper is that a moving conductor experiences viscous damping force when subjected to a magnetic field, due to internal current loss induced by electromotive force. The dynamic equation of the system is formulated by using the Green function method and finite element modeling technique. Simulation of the system is also performed to discuss the pros and cons of the passive magnetic damper in the suppression of a beam vibration.

H∞ 제어에 의한 유연한 로봇조작기의 강건제어

박중윤,박창용 金烏工科大學校 1995 論文集 Vol.16 No.-

Robust Control of a one link flexible robot manipulator is studied. The objective of this paper shows the H∞ robust control for model uncertainty and sensitivity problems of flexible structures. The system is modeled as rigid mode and the first one vibration mode neglecting the other higher degree of vibration modes. H∞ control design is a powerful method for designing robust feedbackcontrol system to achieve the frequency-dependent singular values of shaping specifications. The first, we consider the robust stability analysis for structural uncertainty because of system modeling to overcome the spillover phenomenon. Next, mixed sensitivity problem of robust control system design of good command response, disturbance rejection and noise suppression are considered by achievement of shaping specifications. We show that the feedback system satisfies some design objectives. Simulation results are presented to demonstrate control performance.

유연한 조작기의 진동에 대한 최적 위치 제어

박중윤,황상철 金烏工科大學校 1993 論文集 Vol.14 No.-

Optimal position control of a flexible manipulator is studied. A slender flexible manipulator is modeled as Euler-Bernoulli beam with tip mass and a rigid hub. The vibration system of a flexible manipulator neglecting higher-order elastic vibrating modes is subject to become unstable because of the excitation of the residual modes. The classical control method is usually used is not suitable in this non-minimum phase system. It is shown that the PD control which is known as increasing the system damping is unstable. However, even in the non-minimum phase system, the system is stabilized by the optimal feedback control. LQG/LTR control law is more effective method for controller design of the physical control system than any other optimal control law. LQG/LTR design method and numerical results are presented.