• 드라이브 ㆍ 컨트롤
• /
• 제12권4호
• /
• pp.21-27
• /
• 2015

The accurate position control of pneumatic driving apparatus is considered in this paper. In pneumatically actuated positioning systems, accurate positioning as an electrical servo has been known to be difficult because of the friction force and compressibility of the air. For good control performance of the pneumatic system, an actuator mounted with externally pressurized air bearings is produced to compensate for friction force. For the controller design, the governing equation of the pneumatic driving apparatus is derived. In order to reduce the nonlinear characteristics of the control valve, linearized control input is derived from the relation between the effective area of the valve and the control input. The experimental results are presented to show the results of the improved position control of the pneumatic driving apparatus.

• 드라이브 ㆍ 컨트롤
• /
• 제9권1호
• /
• pp.18-24
• /
• 2012

The paper deals with the design of a new low-friction seal for a pneumatic cylinder with high speed actuation. The seal performance with variation of the cross sections in piston seals with elastomeric material was investigated to minimize the friction forces using ABAQUS. The contact stress and strain distributions and frictional forces of the piston seals were investigated with variation of interference fits, supply pressures and friction coefficients. To develop adequate and productive procedures, the finite element models of the piston seals were created and nonlinear analysis of a seal design was conducted in order to build further knowledge and understanding of the seal's performance characteristics.

• 드라이브 ㆍ 컨트롤
• /
• 제9권2호
• /
• pp.15-20
• /
• 2012

Pneumatic cylinder meter-out driving apparatus is used widely because it is clean, lightweight, and can be easily serviced. In this study an estimation method of energy consumption for pneumatic cylinder meter-out driving apparatus is proposed. The proposed method is derived from state equation and energy equation of air, and, the equation of motion of a moving part of a pneumatic cylinder reflecting the characteristics of the meter-out driving. The effectiveness of the proposed method is proved by simulation study and it demonstrates that the proposed method can evaluate the energy consumption quickly and easily when the parameters of the driving apparatus are changed.

• 유공압시스템학회논문집
• /
• 제8권3호
• /
• pp.21-26
• /
• 2011

Nonlinear seal friction in pneumatic cylinders can impede the performance of pneumatic systems designed for high precision positioning with favorable high speed actuation. The behaviour of an elastomeric piston seals in high speed pneumatic cylinders is analyzed by nonlinear finite element analysis using ABAQUS. The contact pressures, stress and strain distributions and frictional forces of the squeeze type piston seal are simulated with variation of the seal radial installed interference, the operating pressures, friction coefficients and piston rod velocities. The nonlinear finite element model of the squeeze type piston seal is used to predict deformation of a seal, friction force and contact pressure distributions.

• 유공압시스템학회논문집
• /
• 제8권3호
• /
• pp.8-13
• /
• 2011

In the present study, a robust controller has been designed to control force for a pneumatic driving system considering the effect of a transmission line. Transfer characteristics of pneumatic transmission line should be changed according to the velocity of the air going through the transmission line. The designed controller is composed of two parts. The one is a feedback controller, which is composed of a stabilizing filter, a compensating filter of modelling error and a nominal model of the force control system, to compensate the influence of transmission line and improve the feedback characteristics of the control system, and, the other is a feedforward controller to achieve the control performance. Control results with the designed controller show that the robustness and performance of the control system are improved compared to the control results with a fixed gain controller.

• 유공압시스템학회논문집
• /
• 제5권1호
• /
• pp.1-5
• /
• 2008

Pneumatic driving systems have hard non-linear characteristic and large friction force compared with driving power. Hence, it cannot be robust against parameter uncertainties, modelling error, disturbance and noise. In this study, we apply a mixed $H_2/H_{\infty}$ control to the generalized plant for a pneumatic driving apparatus system including parameter uncertainty and disturbance. In order to design the $H_2/H_{\infty}$ controller, we use the LMI technique. To evaluate control performance and robust stability of the designed controller, we compare it with a conventional controller such as PVA(Position-Velocity-Acceleration state controller) using the simulation results. As a result, it can be known that designed controller shows better robust stability than the conventional controller.

• 유공압시스템학회논문집
• /
• 제1권2호
• /
• pp.20-25
• /
• 2004

In this study, a position control characteristics of pneumatic cylinder with transmission line is analyzed. Dynamic characteristics of transmission line using compressible fluid is changed by the flowing stiles of the fluid the diameter and the length of the line. But, the effect of the change of dynamic characteristics of transmission line by the flowing states on the position control characteristics can be neglected because of the friction force of the pneumatic cylinder. So, We assume that the position control characteristics is affected by the diameter and length of the transmission line. The experimental results according to the change of parameter of the transmission line show that the relation between the parameter of the transmission line and the position control characteristics of pneumatic cylinder driving system with the transmission line.

• 유공압시스템학회:학술대회논문집
• /
• 유공압시스템학회 2010년도 춘계학술대회
• /
• pp.99-104
• /
• 2010

Nonlinear seal friction in pneumatic cylinders can impede the performance of pneumatic systems designed for high precision positioning with favorable high speed actuation. The behaviour of an elastomeric piston seal in high speed pneumatic cylinders is analysed by nonlinear finite element analysis using ABAQUS. The contact pressures, stress and strain distributions and frictional forces of the piston seal are simulated with variation of interference fits, supply pressures, friction coefficients and piston rod velocities. The nonlinear finite element model of the piston seal is used to predict deformation of a seal, friction force and contact pressure distributions.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2018년도 추계학술대회
• /
• pp.52-54
• /
• 2018

울산신항 북방파제(제3공구)축조공사에서는 국내 최초로 선박제조용 F/D(Floating Dock)선을 적용하여 케이슨 제작 및 거치공사를 실시하였으며, 공장형 슬립폼 제작장(IP-CCV)를 적용한 경우 보다 공기단축 및 원가절감의 효과가 있었다. F/D선 공법 순서는 작업부두에 F/D선 접안, 케이슨 제작, F/D선 진수장 이동, F/D선 및 케이슨 진수, 케이슨 예인 및 거치의 순서로 시행되었으며, 현재 턴키공사의 설계특화 내용으로 활용되어 시공안정성 향상 및 공기, 공사비 절감 방안으로 적용되고 있다. 향후 남북관계가 원만히 해결되어 동해안 항만개발이 가속화되면 국외특허공법(IP-CCV)에 의존없이 경쟁력있는 공법이라 판단된다.

• 한국건설관리학회논문집
• /
• 제14권2호
• /
• pp.22-34
• /
• 2013

최근 건설 프로젝트가 대형화, 복잡화, 전문화되면서 다양한 참여자들 사이에서 발생하는 방대한 양의 정보 활용이 중요해지고 있다. 특히 이러한 정보는 건설프로젝트에서 주도적인 역할을 담당하는 건설현장에서 주로 생산된다. 건설현장 관련 참여자 간 정보 교환의 미흡은 공기지연, 품질하자와 같은 건설생산성 저해 요인을 유발한다. 이러한 문제점을 해결하기 위하여 건축물의 전 생애주기 동안에 필요한 데이터를 생산하고 관리하는 프로세스인 BIM(Building Information Modeling)에 대한 관심이 높아지고 있다. 그러나 국내에서 BIM의 도입은 주로 설계단계에 집중되어 있으며 시공단계에서 BIM의 활용정도는 미비한 실정이다. 따라서 본 연구는 선행연구 고찰을 통하여 골조공사에서 정보 교환의 미비로 인한 실패요인을 구분하고, BIM의 적용이 가능한 업무를 전문가 면담조사를 통하여 도출할 것이다. 그리고 BIM이 도입된 다수의 골조공사 현장의 분석을 통해 업무별 BIM 지원을 위한 참여자간 정보의 흐름을 실무 수준으로 제안하고 이에 따른 기대효과를 제시하는데 본 연구의 목적이 있다.