• 한국산학기술학회논문지
• /
• 제12권11호
• /
• pp.4751-4755
• /
• 2011

본 연구는 자동차용 시트 Back frame 내부에 설치하여 탑승자의 등부분을 지지하며 편안한 승차감을 제공하는 시트용 서스펜션 시스템에 대한 연구이다. 운전자의 등 전체를 고르게 지지하는 구조로 설계하고 시트 백 프레임과 플라스틱 서스펜션의 조립을 효과적으로 할 수 있는 구조로 개발 하고자 한다. 서스펜션 단품은 운전자의 체압 분포를 고려하여 설계하고 시뮬레이션 해석에 있어서는 실제 모델과 같은 크기를 가지고 하였다. 플라스틱 서스펜션의 해석결과가 실제 측정값에 근접함을 확인하였으며 기존 Wire Type에 비해 양호한 체압분포를 얻을 수 있었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2008년도 춘계학술대회 논문집
• /
• pp.287-288
• /
• 2008

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.322-322
• /
• 2000

This paper shows an application of H$_{\infty}$ control design for a magnetic suspension system which has strongly nonlinearity and parameter perturbation. The control design is evaluated by numerical simulations and experiments.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
• /
• pp.345-346
• /
• 2002

The electrical and rheological properties of a chitosan malonate suspension in silicone oil was investigated by varying the electric fields, volume fractions of particles, and shear rates, respectively. The chitosan malonate susepnsion showed a typical electrorheological (ER) response caused by the polarizability of an amide polar group and shear yield stress due to the formation of multiple chains upon application of an electric field. The shear stress for the suspension exhibited a linear dependence on the volume fraction and an electric field power of 1.88. On the basis of the results, the newly synthesized chitosan malonate suspension was found to be an anhydrous ER fluid.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2010년도 추계학술대회 논문집
• /
• pp.71-76
• /
• 2010

This paper presents the feasibility for improving the ride quality of railway vehicle equipped with semi-active suspension system using magnetorheological(MR) fluid damper. In order to achieve this goal, a fifteen degree of freedom of railway vehicle model, which includes a car body, bogie frame and wheel-set is proposed to represent lateral, yaw and roll motions. The MR damper system is incorporated with the governing equation of motion of the railway vehicle which includes secondary suspension. To illustrate the effectiveness of the controlled MR dampers on railway vehicle secondary suspension system, the sky-hook control law using the velocity feedback is adopted. Computer simulation for performance evaluation is performed using Matlab. Various control performances are demonstrated under external excitation which is the creep force between wheel and rail.

• Wind and Structures
• /
• 제9권4호
• /
• pp.331-344
• /
• 2006

The cable-stayed-suspension hybrid bridge is a cooperative system developed from the traditional cable-stayed and suspension bridges, and takes some advantages of the two bridge systems. It is also becoming a competitive design alternative for some long and super long-span bridges. But due to its great flexibility, the flutter stability plays an important role in the design and construction of this bridge system. Considering the geometric nonlinearity of bridge structures and the effects of nonlinear wind-structure interaction, method and its solution procedure of three-dimensional nonlinear flutter stability analysis are firstly presented. Parametric analyses on the flutter stability of a cable-stayed-suspension hybrid bridge with main span of 1400 meters are then conducted by nonlinear flutter stability analysis, some design parameters that significantly influence the flutter stability are pointed out, and the favorable structural system of the bridge is also discussed based on the wind stability.

• 한국소음진동공학회논문집
• /
• 제21권12호
• /
• pp.1199-1205
• /
• 2011

In the present work, a seat suspension system adopting semi-active damper is evaluated for driver's ride quality. A cylindrical type of ER(electrorheological) damper is designed and manufactured for the seat suspension of heavy vehicles. The governing equation is derived under consideration of human vibration. A sliding mode controller is then synthesized and experimentally realized on the manufactured ER seat suspension while a driver is sitting on the controlled seat. Ride quality is evaluated by fatigue decreased proficiency boundary, vibration dose value and crest factor utilizing weighted-acceleration according to ISO2631.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
• /
• pp.401-404
• /
• 1996

A new method for the electrostatic suspension of disk-shaped objects is proposed which is based on a switched-voltage control scheme. It operates according to a relay feedback control and deploys only a single high-voltage power supply capable of delivering a dc voltage of positive and/or negative polarity. In addition to the unique feature that no high-voltage amplifiers are needed, this method provides a remarkable system simplification relative to conventional methods. It is shown that despite the inherent limit cycle property of relay feedback based control, an excellent performance in vibration suppression is attained due to the presence of a relatively large squeeze film damping. In this paper, the functional principle of the switched voltage control scheme, numerical analysis, stator electrode design, and a nonlinear dynamic model of the suspension system are described. Experimental results will be presented for a 4-inch silicon wafer that clearly reveal the capability of the proposed control structure to suspend the wafer stably at an airgap length of 50 .mu.m.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.438-441
• /
• 1997

This paper studies a semi-active suspension with ER damper controlled Fuzzy Net Controller designed GA(Genetic Algorithm). Apparent viscosity of ERF(Electro-Rheological Fluid) can be changed rapidly by applying electric field. Semi-active suspension for ground vehicles are expected to improve ride quality with less vibration. This paper deals with a two-degree -of-freedom suspension using the ER damper for a quarter vehicle system. In this paper, the GA is applied for generating Fuzzy Net Controllers. The GA designs the optimal structure and performance of Fuzzy Net Controller having hybrid structure. Computer simulation results show that the semi-active suspension with ER damper has good performances of ride quality.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.704-709
• /
• 2004

This paper presents the laser processing to adjust the roll and pitch directions of the flex suspension assembly for hard disk drive production. The adjustment is accomplished using a number of laser beam projections that can be approximated using the regression model of the existing measured roll and pitch directions. Information derived from the analysis can be applied to control the quality of flex suspension assembly. The performances of the proposed technique were observed using the flex suspension assembly plant in Thailand as an illustrative case study. The experimental results are given to support the improving manufacturing yields and some economic benefits of the proposed technique.