• The Journal of the Convergence on Culture Technology
• /
• v.8 no.5
• /
• pp.591-596
• /
• 2022

Since 4-bar linkage widely used in various industrial fields has a fixed link length, it is inconvenient to add an independent link structure or control device to change the movement of output link. Therefore, this paper proposes a new concept of variable 4-bar linkage mechanism to selectively adjust the movement of the output link to fit desired situations, and applied to the commercial table fans, which is a representative product using a 4-bar linkage system. The optimal rotation angle steps for efficiency are determined experimentally and the appropriate lengths of linkage to fit each step are calculated analytically. Changes in the linkage length are implemented by the rotational motion using a grooved cylindrical cam and the feasibility of the proposed variable linkage mechanism is verified through fabrication and measurement. The presented variable link mechanism is expected to improve the efficiency of industrial robots and fuel valve systems.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.6 no.2
• /
• pp.9-14
• /
• 2012

In this study, an advanced knee joint for active prosthesis leg driven by a linear actuator is suggested. The structure of knee joints of existing active prosthesis legs consists of three links. This kind of linkage requires large torque to drive the active prosthesis legs. Thus a new linkage structure is suggested to solve such problem in this paper. Motion characteristics of the suggested linkage are examined in the simulation. The motion simulation results show that the proposed linkage is able to imitate human gait cycles with the half of linear actuator speed in existing linkages.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.7
• /
• pp.851-858
• /
• 2011

Nanopositioning technologies play an important role in the progress of electronics, optics, bio-engineering and various nano-scale technologies. As a result, various practical nanopositioning methods have been successfully introduced. Flexure mechanism is a valuable method in nanopositioning because of smooth and friction-free motion and the infinitesimal movement near to sub-nm. In this study a modularized nanopositioner based on parallelogram four-bar linkage structure with right-circular flexure hinge was developed. The positioning performance of a single axis nanopositioner and a XY nanopositioner which was extended from single axis one were demonstrated using control experiments. Consequently, it was shown that the developed single axis nanopositioner possessed high performance and could be extended to various multi-axis nanopositioners.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.05a
• /
• pp.541-542
• /
• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.67-68
• /
• 2006

In this paper, a new revolute cooperating robot arms with 12 d.o.f was developed for autonomous moving robots. The robot ann was designed to have the load capacity of 10 Kg. For this, a new joint actuator based on the fourbar link mechanism was employed. As a control system for the robot arm, a distributed control system was developed composed of the main controller and five motor controller for the ann joints. The main controller and the motor controller were developed using the ARM microprocessor and the TMS320c2407 processor, respectively. To validate the performance of the robot system, an experiment to support 10 Kg payload was performed.

• Journal of agriculture & life science
• /
• v.52 no.6
• /
• pp.127-138
• /
• 2018

In this study, the operational characteristics of a domestic vegetable transplanter were investigated. The main functional components and power path of the tranplanter were analyzed. The link structure of transplanting device waskinematically analyzed, and 3D modeling and dynamic simulation were performed. Based on this analysis, the trajectory of the bottom end of the transplanting hopper was analyzed. Also, the plant spacing according to the engine speed and the shifting stage of transplanting transmission was analyzed and verified by field test. As main results of this study, the transplanting device is one degree of freedom(DOF) 4-bar link type mechanism which comprises 10 links and 13 rotating joints. The transplanting hopper plants seedlings in a vertical direction while maintaining a constant posture by the links of transplanting device. The power is transmitted to both the driving part and transplanting part from the engine, and the maximum and minimum plant spacing of the transplanting device were 428.97 mm and 261.20 mm.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.1
• /
• pp.459-464
• /
• 2024

The purpose of this study is to design a toilet lifting seat to prevent falls accidents in the elderly while using the toilet. Prior to design, laws and national standards related to restroom use were investigated and the available space for the assistive devices to be installed was determined. In additions, considering the body size and operating range of the elderly, the optimal final position of the toilet seat is set so that users can use it more safely and conveniently without external help. Moreover, in order to provide an effective standing assistance function, a complex 4-bar link structure was applied to enable simultaneous seat elevation and angle adjustment when operating the device, and the appropriate link shape and dimensions were determined using a linkage program and UG NX. FEA analysis using ANSYS Workbench is performed to ensure the robustness of the stretched linkage and the feasibility of the lifting seat is verified through fabrication.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.9
• /
• pp.42-47
• /
• 2021

A one-touch descending lifeline that can easily be installed and rapidly evacuated in the event of a fire accident in high-rise buildings was proposed to overcome difficulties of conventional descending lifeline such as complex installation methods and procedures. However, this lifeline exhibits limitations such as restrictions in installation location and large apparatus size. Therefore, this paper proposes a sliding-type descending lifeline, which has a similar operation to that of current one-touch descending lifeline and solves the aforementioned limitations. A double square link mechanism including a sliding four-bar linkage is proposed and the descending lifeline support is redesigned to unfold in two different planes, allowing 3D movement. Additionally, the shape of the support frame is designed to obtain two attachment surfaces that can be attached to a wall, irrespective of the angle between the window and the inner wall. FEA analysis using ABAQUS is performed to ensure that the robustness of the presented support complies with the Fire Control Act Enforcement Decree. Finally, the feasibility of the proposed sliding one-touch descending lifeline is verified through fabrication.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.12
• /
• pp.1585-1591
• /
• 2011

In this paper, we present a new exoskeleton-type data glove that can sense the movement of the human finger and reflect the force to the finger. The data glove is designed on the basis of the skeletal structure of the human hand, and the finger module has 1 degree-of-freedom because it includes three four-bar mechanism joints in series and a wire-coupling mechanism. In addition, the transmission ratio of the finger module is maintained at 1:1.4:1 over the entire movement range, and hence, the module can perform both extension and flexion. In addition, to enable adduction/abduction motion of the human hand, a unique MCP joint is designed by using two universal joints. To validate the feasibility of the data glove, master-slave control experiments based on force-position control between the data glove and the robot hand are conducted.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.11
• /
• pp.1405-1411
• /
• 2012

Remote handling manipulators are widely used for performing hazardous tasks, and it is essential to ensure the reliable performance of such systems. Toward this end, tendon-driven mechanisms are adopted in such systems to reduce the weight of the distal parts of the manipulator while maintaining the handling performance. In this study, several approaches for the design of a gripper system for a tendon-driven remote handling system are introduced. Basically, this gripper has an underactuated spring mechanism that is combined with a slave manipulator triggered by a master operator. Based on the requirements under the specified tendon-driven mechanism, the connecting position of the spring system on the gripper mechanism and kinematic influence coefficient (KIC) analysis are performed. As a result, a suitable combination of components for the proper design of the target system is presented and verified.