• The Journal of Korea Robotics Society
• /
• v.12 no.1
• /
• pp.78-85
• /
• 2017

This paper presents the development of a 3D printer based piezo-driven vertical micro-positioning stage. The stage consists of two flexure bridge structures which amplify and transfer the horizontal motion of the piezo-element into vertical motion of the end-effector. The stage is fabricated with ABS material using a precision 3D printer. This enables a one-body design eliminating the need for assembly, and significantly increases the freedom in design while shortening fabrication time. The design of the stage was optimized using response surface analysis method. Experimental results are presented which demonstrate 100nm stepping in the vertical out-of-plane direction. The results demonstrate the future possibilities of applying 3D printers and ABS material in fabricating linear driven motion stages.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.1
• /
• pp.17-24
• /
• 2006

This study was performed to figure out spray behavior and fuel atomization characteristics of a piezo-driven injector and a solenoid-driven injector in the common-rail injection system under the same design parameters and test conditions. The process of spray injection was visualized by using the spray visualization system composed of a Nd:YAG laser and an ICCD camera. The atomization characteristics were investigated in terms of axial mean velocity, Sauter mean diameter(SMD) and droplet distributions obtained from a phase Doppler particle analyzer system. Compared with solenoid-driven injector, the piezo-driven injector has short injection delay and reaches quickly to the maximum injection value. Spray tip penetration shows some difference, however, spray angle of piezo-driven injector is wider than that of solenoid-driven injector. Sauter mean diameter of piezo-driven type injector is smaller than that of solenoid-driven type.

• Proceedings of the KIEE Conference
• /
• 1991.07a
• /
• pp.60-63
• /
• 1991

Nowadays inverters are widely used for energy-saving and factory automation. Accordingly the characteristics and functions of the inverter are well understood. To our surprise, the characteristics and functions of the inverter-driven induction motor are not well understood. In this technical review, the electrical and mechanical characteristics of the inverter-driven motor, the optimal combination of the inverter with motor, the special design of the inverter-driven motor, and the application of the inverter with the existing motor are given, based on ABB Drives' experiences and technical data.

• The Journal of Korea Robotics Society
• /
• v.9 no.3
• /
• pp.178-184
• /
• 2014

Tendon driven robot mechanisms have many advantages such as allowing miniaturization and light-weight designs and/or enhancing flexibility in the design of structures. When designing or analyzing tendon driven mechanisms, it is important to determine how the tendons should be connected and whether the designed mechanism is easily controllable. Graph representation is useful to view and analyze such tendon driven mechanisms that are complicatedly interconnected between mechanical elements. In this paper, we propose a method of generalized graph representation that provides us with an intuitive analysis tool not only for tendon driven manipulators, but also various other kinds of mechanical systems which are combined with tendons. This method leads us to easily obtain structure matrix - which is the one of the most important steps in analyzing tendon driven mechanisms.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1662-1667
• /
• 2005

In this paper, analysis, design, control and prototype construction of a wearable wire-driven haptic interface called HapticPen is discussed. This device can be considered as a wire driven parallel mechanism which three wires are attached to a pen-tip. Wire tensions are provided utilizing three DC servo motors which are attached to a solid frame on the user's body. This device is designed as input as well as output device for a wearable PC. User can write letters or figures on a virtual plate in space. Pen-tip trajectory in space is calculated using motor encoders and force feedback resulting from contact between pen and virtual plate is provided for constraining the pen-tip motion onto the virtual plane that can be easily setup by arbitrary non-collinear three points in space. In this paper kinematic model, workspace analysis, application analysis, control and prototype construction of this device are presented. Preliminary experiments on handwriting in space show feasibility of the proposed device in wearable environments.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.687-688
• /
• 2013

• Proceedings of the Korea Information Processing Society Conference
• /
• 2005.11a
• /
• pp.377-380
• /
• 2005

최근 다양한 분야에서 임베디드 소프트웨어의 비중이 증대함에 따라 품질 요구 사항이 증대 하였지만, 현실적인 개발 일정은 점점 줄어들고 있다. 이에 본 논문에서는 임베디드 소프트웨어의 기민한 속성 주도 설계(Agile Attribute-Driven Design)를 체계적으로 적용하기 위한 '통합 분석 기법'을 정의한다. 그리고 이를 통한 기민한 설계 접근법을 제안한다. '통합 분석 기법'은 임베디드 소프트웨어의 특성을 고려한 기능 분석과 동시에 '품질 속성 시나리오'를 분석할 수 있는 기법으로서 고품질의 아키텍처 구축을 목적으로 한다. 또한 본 논문에서는 개미 로봇 구현 사례를 통해 '통합 분석 기법'을 검증하고 효과를 확인한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1997.10a
• /
• pp.50-57
• /
• 1997

A 600HP class high-speed gear driven 3-stage turbo-compressor (IGCC : Integrally Geared Centrifugal Compressor) driven by a 3600 rpm AC induction motor has been designed, of which low speed pinion runs at 35000 rpm and high speed pinion at 50000 rpm nominally. Due to its high speed operation, the system requires very reliable bearing selection and design as well as accurate rotordynamic analysis and prediction of its dynamic behavior to secure the operating reliability. Rotordaynamic analyses of the IGCC rotor-bearing system predicted that the low speed pinion rotor mounted on 5-pad tilting pad bearings has two critical speeds before its design speed and high speed pinion rotor only one critical speed, and estimated critical speeds of both pinion shafts are away from the continuous operating speed enough to satisfy the corresponding API requirement. The forced response analysis with API specified maximum allowable unbalances also showed that unbalance responses are small enough for smooth operation of the system.

• The Journal of Korea Robotics Society
• /
• v.14 no.3
• /
• pp.203-210
• /
• 2019

This paper proposes a hand-controller mechanism for manually controlled endoscopic surgical instruments. A wire-driven mechanism is typically adapted for endoscopic surgical tools because motors cannot be embedded to the joints due to the size limitation. The wire-driven mechanism requires length control of wires that are pulled and released according to the desired joint angle. It is difficult for the operator to control individual wire lengths intuitively. The hand-controller mechanism should be able to control the wires easily without complex processes. For this purpose, we propose a mechanism that can control the wire lengths with a simple mechanical structure and its optimal design method using genetic algorithm. We show the simulation and experimental results to confirm the proposed mechanism and design methods are useful for the manually controlled endoscopic surgical instrument.

• Journal of the Society of Naval Architects of Korea
• /
• v.59 no.3
• /
• pp.183-191
• /
• 2022

A design method for a propeller type rim-driven axial-flow turbine for a micro-hydropower system is presented. The turbine consists of pre-stator, impeller and post-stator, where the pre-stator plays a role as a guide vane to provide circumferential velocity to the on-coming flow, and the impeller as a rotational power generator by absorbing angular momentum of the flow. BEM(Blade Element Method), which is based on the turbine Euler equation, is employed to design the pre-stator and impeller blades. NACA 66 thickness form and a=0.8 mean camber line, which is widely accepted as a marine propeller blade section, is used for the pre-stator and turbine blade section. A CFD method, derived from the discretization of the RANS equations, is applied for the analysis of the designed turbine system. The design conditions of the turbine is confirmed by the CFD calculation. Turbine characteristic curve is calculated by the CFD method, in order to provide the performance characteristics at off-design operation conditions. The proposed procedures for the design of a propeller type rim-driven axial-flow turbine are established and confirmed by the CFD analysis.