• Journal of the Korean Society for Precision Engineering
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• v.27 no.5
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• pp.102-111
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• 2010

This paper presents a design of seat mechanism for multi-postures controllable wheelchair. The possible seat postures are reclining, tilting, standing, which are controlled by four seat mechanisms using four linear actuators. The seat mechanisms designed in this study are reclining, tilting, forward-tilting, and elevation mechanism. Three postures except standing are controlled by corresponding mechanisms, but the standing posture is performed by combination of the reclining and the forward-tilting mechanism. Posture control system is composed of PID controllers and a planner to determine a feasible posture based on a posture transition diagram. Simulation results show that the seat mechanism and its control system are applicable to a multi-postures controllable wheelchair.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.4
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• pp.281-285
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• 2017

Since the performance of the spring operating mechanism for a circuit breaker mainly depends on the dynamic behavior and mass of the coil spring, its dynamic analysis is required to evaluate the performance of the spring operating mechanism. In this study, a coil spring design program is developed for the spring operating mechanism. An experimental approach is used to find the variables satisfying the design constraints' requirements. The coil spring is formed by using a lumped mass spring model. This program offers reference data for the design of coil springs and for the spring operating mechanism.

• Journal of the Korean Society for Railway
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• v.6 no.4
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• pp.300-307
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• 2003

Using a conventional railway, a tilting train was applied as a means of improving vehicle speed curve negotiation without any modification of infrastructure. In order to achieve the optimal car-body position control through the tilting mechanism, a dynamics analysis was required after the kinematics analysis of the tilting mechanism. For this, the geometric relationship of the linkage-type tilting mechanism was defined. Then, the equations of motion for the half car-body were derived. With the derived equations, the effect of the parameter change on performance was analyzed. The analysis result can be used in the optimum design of a tilting mechanism that considers the track environment, vehicle and operational conditions in which the tilting vehicle is applied.

• Journal of the Semiconductor & Display Technology
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• v.6 no.1 s.18
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• pp.37-41
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• 2007

Recently PZT is used in ultra precision mechanism field. PZT has a small motion range although it has a high resolution. Many methods, such as inchworm, impact driving, etc., have been applied for the expansion of the motion range.? In this study, the new actuating mechanism for rotational motion with two PZT actuators is proposed. The ultra precision rotational actuator which is made by proposed mechanism is able to operate both coarse and fine motion. The design parameters of the proposed mechanism are considered to improve the performance of the system. The rotational stage which is applied by the proposed mechanism is fabricated. The resolution and velocity for fabricated rotational stage are measured by laser interferometer.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.5
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• pp.464-472
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• 2006

This paper presents the two degree-of-freedom (DOF) planar parallel mechanism, called the $2{\underline{R}}RR-RP$ manipulator, whose degree-of-freedom is dependent on an additional passive constraining leg connecting the base and the platform. First, the kinematic analysis of the mechanism is performed: the inverse and forward kinematic problems are analytically solved, the workspace is systematically derived, and all of the singular configurations are examined. Then, in order to determine the geometric parameters the optimization of the mechanism is performed considering its dexterity, stiffness, and space utilization. Finally, the kinematic performances of the optimized mechanism are evaluated through the comparison study to the conventional 5-bar parallel manipulator.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.484-489
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• 1998

In this paper, we examine the displacement characteristics of the parallel leaf spring mechanism with large-deflective elastic hinges, and the validity of this mechanism as a translational and rotational mechanism is confirmed with multi-input system. This study is focused on the linear driving force as an input force, which is applied to the large-deflective elastic mechanism, and the displacement characteristics are discussed with theoretically and experimentally. The motions of this mechanism due to large-deflective hinges are changed by the position of loading force regardless of a single driving force. The numbers of degree of freedom are increased with the hinges, and we can be used to a multiple driving force in order to obtain many types of Output.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.501-505
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• 2016

In this study, a robot is implemented in H/W based on four-bar linkage mechanism and Jansen mechanism. Our goal is to finish the given path using given terms. The various programs was used to understand the mechanism in more detail. DISON m.Sketch, EDISON Designer, Theo Jansen Mechanism Optimization Solver. Using these programs, we can design the robot in more dtails and reduce errors and trials. For the design and implementation of a robot, it is need to get joint variable, a foot point, and their relation. Thus, the proposed kinematic analysis is very important process for the design and implementation of legged robots.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.11
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• pp.76-82
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• 1998

In this study, the Ball screw and Servo motor Mechanism is considered as a High Speed Tool Feed System for the machining of a piston of a reciprocating engine. For the machining of a piston, that shapes oval, high speed servo mechanism is needed as a positioning of a cutting tool, and the stroke of tool is 0.1 mm ~ 1 mm. Ball screw and servo motor Mechanism is available very much because this mechanism is used widely in general machine. This Mechanism has been designed with the use of the decrease in mass and partial wear of the ball screw for high speed positioning of tool. Also the periodic learning control method with the inverse transfer function compensation has been applied to the positioning control for the high accuracy positioning of tool. These applications lead the achievement of the machining of a piston with an accuracy of 5${\mu}{\textrm}{m}$ at 2500 rpm in CNC turning.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.9
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• pp.148-155
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• 1995

The object of this study is to achieve a gteater understanding of meterial removal process and its mechanism. In this study, some applications of finite element techniques are applied to analyze the chip formation and cutting heat generation mechanism of metal cutting. To know the effect of cutting parameters, simulations employed some independent cutting variables change, such as constitutive deformation laws of workpiece and tool material, frictional coefficients and tool-chip contact interfaces, cutting speed, tool rake angles, depth of cut and this simulations also include large elastic-plastic defor- mation, adiabetic thermal analysis. Under a usual plane strain assumption, quasi-static, thermal-mechanical coupling analysis generate detailed informations about chip formation process and cutting heat generation mechanism Some cutting parameters are affected to cutting force, plastic deformation of chip, shear plane angle, chip thickness and tool-chip contact length and reaction force on tool, cutting temperature and thermal behavior. Several aspects of the metal cutting process predicted by the finite element analysis provide information about tool shape design and optimal cutting conditions.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.493-497
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• 2016

Walking mechanism, there are many types. Prior to the modeling and design, we thought about a variety of mechanisms based on the Janssen mechanism to design a walking mechanism optimized for walking. The more the legs increases the stability of the structure, while the weight is heavy and if that advantage had the disadvantage, the legs are easier to walk in the utilization and structural aspects of the torque had fewer advantages. The disadvantage is that the instability mechanism, four-legged, but improve it and look forward to the idea of utilization and cost-effectiveness, its future utilization will be endless. To study this, we utilized a variety of software, such as m-sketch, Edison design program, we have seen the actual production through scientific experiments box.