• 로봇학회논문지
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• 제11권1호
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• pp.26-32
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• 2016

A variable release torque-based compliance spring-clutch (VCSC) is presented. VCSC is a safe joint to reduce the impact of collisions between humans and robots. It is composed of four functional plates, balls, springs to make some functions in compliant movement, release mechanism, gravity compensation during its work. Also, it can estimate torque applied to a joint by using distance sensor and parameters of cam profile. The measured variable torque of prototype is 4.3~7.6 Nm and release torque is 4.3 Nm. In our future studies, a calibration for torque estimation will be conducted.

• 설비공학논문집
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• 제11권6호
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• pp.716-724
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• 1999

In co-orbiting scroll compressor, the two scroll members are to orbit with independent radii, producing a relative orbit motion between them. One scroll member is driven by the crank mechanism while the motion of the other member is determined by geometrical constraints and reacting forces. This paper presents an analytical study on the performance of a co-orbiting scroll compressor. The following results have been obtained: Radial contact force between the scroll wraps is virtually free from the centrifugal force of the orbiting scroll member. The frictional losses are somewhat increased due to the complicated drive mechanism, yielding to a little lower EER compared to conventional radially compliant scroll compressors .

• Advances in robotics research
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• 제1권1호
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• pp.1-19
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• 2014

Microgripper is an essential device in the micro-operation system. It can convert other types of energy into mechanical energy and produce clamp movement with required chucking force, which enables it a broad application prospect in the domain of tiny components' processing and assembly, biomedicine and optics, etc. The performance of a microgripper is dependent on its power supply, type of drive, mechanism structure, sensing components, and controller. This paper presents a state-of-the-art survey of recent development on flexure-based microgrippers. According to the drive type, the existing microgrippers can be mainly classified as electrostatic microgripper, electrothermal microgripper, electromagnetic microgripper, piezoelectric microgripper, and shape memory alloy microgripper. Additionally, some different mechanisms, sensors, and control methods that are used in microgripper system are reviewed. The key issue of how to choose those components in microgripper system design is also addressed.

• 로봇학회논문지
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• 제19권1호
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• pp.1-7
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• 2024

This paper presents an under-actuated robotic hand inspired by the ligamentous structure of the human hand for a prosthetic application. The joint mechanisms are based on the concept of a tensegrity structure formed by elastic strings. These rigid bodies and elastic strings in the mechanism emulate the phalanx bones and primary ligaments found in human finger joints. As a result, the proposed hand inherently possesses compliant characteristics, ensuring robust adaptability during grasping and when interacting with physical environments. For the practical implementation of the tensegrity-based joint mechanism, we detail the installation of the strings and the routing of the driving tendon, which are related to extension and flexion, respectively. Additionally, we have designed the palm structure of the proposed hand to facilitate opposition and tripod grips between the fingers and thumb, taking into account the transverse arch of the human palm. In conclusion, we tested a prototype of the proposed hand to evaluate its motion and grasping capabilities.

• 제어로봇시스템학회논문지
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• 제21권6호
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• pp.524-530
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• 2015

Early wearable robotic devices were big, powerful and manipulator-like. Recently, various applications of wearable robotics have shown a greater demand for lower weight and compliancy. One approach to achieve these objectives is the use of novel actuators such as twisted string actuators. These actuator are very light, quiet, mechanically simple and compliant. Therefore, they can drastically decrease the weight and size of robotic systems such as exoskeletons. However, one drawback of this actuator is its nonlinear transmission ratio, which is established as a ratio between the angle of twisting of the strings and their resulting contraction. In this paper, we propose a transmission mechanism with rotational motion as the output incorporating a twisted string actuator (TSA). The designed mechanism allows the linearization of the relationships between the input and output displacements and forces of a TSA. The proposed design has been validated theoretically and through a set of computer simulations. A detailed analysis of the performance of the proposed mechanism is presented in this paper along with a design guideline.

• 한국정밀공학회지
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• 제21권2호
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• pp.203-209
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• 2004

Compliant bi-stable mechanism allows two stable states within its operation range staying at one of the local minimum states of the potential energy. Energy storage characteristics of the bi-stable mechanism offer two distinct and repeatable stable states, which require no power input to maintain it at each stable state. This paper suggests an equivalent model of the chevron-type bi-stable microactuator using the equivalent spring stiffness in the rectilinear and the rotational directions. From this model the range of spring stiffness where the bi-stable mechanism can be operated is analyzed and compared with the results of the FEA (Finite Element Analysis) using ANSYS for the buckling analysis, both of which show a good agreement. Based on the analysis, a newly designed chevron-type bi-stable MEMS actuator using hinges is suggested for the latch-up operation. It is found that the experimental response characteristics of around 36V for the bi-stable actuation for the 60$mu extrm{m}$ stroke correspond very well to the results of the equivalent model analysis after the change in cross-sectional area by the fabrication process is taken into account. Together with the resonance frequency experiment where 1760Hz is measured, it is shown that the chevron-type bi-stable MEMS actuator using hinges is applicable to the optical switch as an actuator.

• 한국지능시스템학회논문지
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• 제23권1호
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• pp.12-17
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• 2013

본 논문에서는 컴플라이언스 특성의 발을 갖는 이족 로봇의 다리 메커니즘을 제시한 후, 이족 로봇을 위한 전형적인 보행 패턴에서 발의 접촉 반발력과 이것이 무릎과 힙 관절에 미치는 영향을 고찰하고자 한다. 이러한 분석은 보행 로봇이 걸음 동작을 수행할때, 발의 물리적인 접촉력의 영향을 파악하는데 있어서 유용하고, 다리 메커니즘의 관절 사양을 결정하는데 활용될 수 있다. 결과적으로, 로봇 발 메커니즘의 컴플라이언스 특성이 발의 접촉 반발력에 의해 영향을 받는 보행 다리 관절의토오크 특성을 완화시키는데 기여할 수 있음을 보인다.

• Composites Research
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• 제22권6호
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• pp.7-12
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• 2009

본 연구는 압전 작동기 기반 초소형 날갯짓 비행체의 날갯짓 운동을 위해, 압전 작동기의 펌핑 운동을 효과적으로 날갯짓 운동으로 변환하는 힌지 메커니즘 제작 기법에 대해 다루었다. 경량화를 위해 탄소섬유/에폭시(Graphite/Epoxy) 프리프레그를 사용하고, 반복적인 제작이 용이하도록 레이저 절단기를 활용하였으며, 힌지부는 얇은 캡톤 필름을 이용해 컴플라이언트(compliant) 메커니즘으로 구성하였다. 제작된 힌지 메커니즘을 압전 유니모프 작동기 PUMPS에 연결하여 동작시켜 본결과, 300V 170Hz 인가 전압에서 $173^{\circ}$의 큰 날갯짓 각을 가짐을 확인하였다.

• Transactions on Control, Automation and Systems Engineering
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• 제4권1호
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• pp.100-107
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• 2002

The advanced bilateral control algorithm, which can enlarge a reflected force by combining force reflection and compliance control, greatly enhances workability in teleoperation. In this scheme the maximum boundaries of a compliance controller and a force reflection gain guaranteeing stability and good task performance greatly depend upon characteristics of a slave arm, a master arm, and an environment. These characteristics, however, are generally unknown in teleoperation. It is, therefore, very difficult to determine such maximum boundary of the gain. The paper presented a novel method for design of an advanced bilateral controller. The factors affecting task performance and stability in the advanced bilateral controller were analyzed and a design guideline was presented. The neurofuzzy compliance model (NFCM)-based bilateral control proposed herein is an algorithm designed to automatically determine the suitable compliance for a given task or environment. The NFCM, composed of a fuzzy logic controller (FLC) and a rule-learning mechanism, is used as a compliance controller. The FLC generates compliant motions according to contact forces. The rule-learning mechanism, which is based upon the reinforcement learning algorithm, trains the rule-base of the FLC until the given task is done successfully. Since the scheme allows the use of large force reflection gain, it can assure good task performance. Moreover, the scheme does not require any priori knowledge on a slave arm dynamics, a slave arm controller and an environment, and thus, it can be easily applied to the control of any telerobot systems. Through a series of experiments effectiveness of the proposed algorithm has been verified.

• 전기학회논문지
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• 제65권12호
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• pp.2030-2036
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• 2016

This paper presents a hardware development procedure of the ASB(Active Seat Belt) control system to comply with ISO 26262. The ASIL(Automotive Safety Integrity Level) of an ASB system is determined through the HARA(Hazard Analysis and Risk Assessment) and the safety mechanism is applied to meet the reqired ASIL. The hardware architecture of the controller consists of a microcontroller, H-bridge circuits, passive components, and current sensors which are used for the input comparison. The required ASIL for the control systems is shown to be satisfied with the safety mechanism by calculation of the SPFM(Single Point Fault Metric) and the LFM(Latent Fault Metric) for the design circuits.