• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.5
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• pp.660-666
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• 2011

In this paper, we proposed a Particle Swarm Optimization(PSO) to search the optimal link lengths for legged walking robot. In order to apply the PSO algorithm for the proposed, its walking robot kinematic analysis is needed. A crab robot based on four-bar linkage mechanism and Jansen mechanism is implemented in H/W. For the performance index of PSO, the stride length of the legged walking robot is defined, based on the propose kinematic analysis. Comparative simulation results present to illustrate the viability and effectiveness of the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.339-340
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• 2013

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.464-466
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• 2014

The mechanism synthesis methods, graphical, analytical and computer-aided technique have been proposed for selecting and scaling mechanical system. According to developing computation tools, mechanism could be synthesized much faster and more correct than previous analytical ways by improved techniques. In this paper, the improved synthesis method is proposed to solve body guidance synthesis problem. To perform the mechanism synthesis for body guidance, a planar linkage is modeled as a set of free three bushings located in design space. The values of bushing stiffness and x, y position of bushings yielding a desired functional requirement related to input motion are found by using an optimization technique.

• Journal of Biosystems Engineering
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• v.28 no.1
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• pp.19-26
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• 2003

An oscillating digger mechanism was designed, constructed. and tested. The mechanism is consisted of a six-bar linkage, one four-bar linkage was fer the digger blade and the other one fur variable soil-crop separation. Experimental variables were amplitude(3, 6, 9 mm). frequency(11.2, 14.9. 17.0 Hz), and forward speed of tractor(0.91, 1.13, 1.56 km/h). Each combination of these variables was replicated three times to measure the draft and torque for power requirement evaluation. and the broken-up soil height on the soil separation sieve mechanism. Four parameters λ(the ratio of vibration speed to forward velocity), p(the ratio of vibration acceleration to forward velocity), K(the ratio of vibration acceleration to gravitational acceleration), and T(the product of λ and K) were induced from three experimental variables: amplitude, frequency, and tractor speed. And the power requirement and soil separation ability were analyzed by regression. Though λ and K were known to be the representative parameters. T was the most moderate one to explain draft. torque. and soil separation in this study. It was estimated that the T equal to or greater than 2.4 was the minimum recommended value. Figure 18 would be useful fir the selection of amplitude. frequency, or operating tractor speed once any two variables are known.

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

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.384-388
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• 2016

This paper proposed a m.Sketch to search the optimal link lengths for a legged walking robot. In order to apply the m.Sketch for the proposed, set the design parameters of the constraints and use the m.Skecth to get optimal GL(Groud Length) and GAC(Ground Angle Coefficient). The legged robot designed based on four-bar linkage theory and Theo Jansen mechanism. The stride length of the legged walking robot was defined based on the proposed kinematic analysis. Use the Edison Design m.Sketch simulate and find the optimal link length having the best of the Ground Length (GL) and Ground Angle Coefficient(GAC). And use these length implemented the Theo Jansen mechanism both in Science box parts and acrylic. In addition to the further expansion of the legs to reach the goaltranslating heavy objects or person.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.502-503
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• 2014

• Journal of Biosystems Engineering
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• v.8 no.2
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• pp.26-38
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• 1983

Binder harvesters introduced to Korea were originally designed to be used for Japonica varieties which are highly resistant to shattering. In order to improve the performance of the binder to Indica varieties which are easily shattered and have shorter stem, mechanical modifications of the binder are inevitable. Shattering losses of the binder can be classified into two major parts; one incurred before and one after binding operations. The latter has been evaluated as great as the former. Previous studies indicated that the high discharge losses resulted from a great impact force of the discharge arm on the rice bundle during the discharge process. This study was intended to theoretically analyze the discharge mechanism of four-bar linkage. For this purpose, two commercially available binder harvesters having a four-bar linkage as a discharge mechanism were analyzed. Using the results from the motion analysis and the other structural constraints of the machines, they were modified and experimentally compared with the machines without modification to see whether any decrease in grain losses was obtained. The results obtained in this study are summarized as follows: 1. The path, velocity and acceleration of discharge arm were computer analyzed by vector analysis. Using results of the analysis and intrinsic constraints of the binder, discharge mechanism was modified to reduce the impact force on bundle by discharge arm in the range where the discharge performance was not deteriorated. This modification of the discharge mechanism could be done with an aid of four-bar linkage synthesis technique. As a result, average velocity and acceleration of the discharge arm during the discharge process were reduced respectively by 19 percent and 33 percent for binder A, and 17 percent and 35 percent for binder B. 2. Through the modification of the discharge mechanism, discharge losses of binder A were reduced by 42-56 percent for Milyang 23, Poongsan and Hangang chal, and discharge losses of binder B were reduced by 13-20 percent for Milyang 23 and Poongsan. 3. Discharge losses were decreased as the bundle size became larger and the size effect on the decrease rate appeared more significant in the binders with modifications than in those without modifications.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.159-164
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• 2011

In this study, a crab robot is implemented in H/W based on four-bar linkage mechanism and Jansen mechanism, and its kinematics is analysed. A vision camera is attached to the mechanism, which makes the proposed robot a kind of biologically inspired robot for image acquisition. Three ultrasonic sensors are adopted for obstacle avoidance. In addition, the biologically inspired robot can achieve the mission appointed by a programmer outside, based on RF and Blue-tooth communication module. For the design and implementation of a crab 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.

• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.107-115
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• 2017

In this paper, four-bar linkage mechanism for the knee joint is developed which is used in prosthetics. But unlike the prosthetics, the feature of this mechanism is that the instantaneous center of rotation of the four-bar linkages can be moved behind the ground reaction force vector so that it can be passively supported without any external power. In addition, this mechanism is developed similar to the structure of the human knee joint for eliminating the sense of heterogeneity of the wearer. In order to design the mechanism with these two objectives, optimization design process is done using the PIAnO tool and detailed design is carried out through optimized variable values. The developed mechanism is attached to the robot which can assist the hip and ankle joints. In order to verify the operation of the developed knee mechanism, an insole type sensor was attached to the shoes to compare data values before and after wearing the robot. Result data showed that wearer wearing the exoskeleton robot with the knee mechanism was the same value regardless of whether the heavy tool is loaded or not.