• 한국운동역학회지
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• 제14권1호
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• pp.183-187
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• 2004

• 대한기계학회논문집A
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• 제20권2호
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• pp.414-430
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• 1996

In this paper, a new kinematic structure of a parallel manipulator with six Cartesian degrees of freedom is proposed. It consists of a platform which is connected to a fixed base by means of 3-PPSP(parameters P, S denote the prismatic, spherical joints) subchains. Each subchain has a link which is concected to a passive prismatic joint at the one end and a passive spherical joint at the other. The spherical joint is then attached to perpendicularly arranged prismatic actuators which are fixed at the base. The spherical joint is then attached to perpendicularly arranged prismatic actuators which are fixed at the base. This arrangement provides a basis to control all six Cartesian degrees of motion of the platform in space. Due to its efficient architecture, the colsed-form solutions of the inverse and forward kinematics can be obtained. As a consequence, this new kinematic structure can be servo controlled using simple inverse kinematics becaese forward kinematics allows for measuring the platform's position and orientation in Cartesian space. Furthermore, the proposed structure provides an effective functional workspace. Series of simulations are performed to verify the results of the kinematics analyses.

• 한국정밀공학회지
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• 제20권3호
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• pp.97-104
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• 2003

This paper proposes a new parallel manipulator fur plane motion, and then discusses on the workspace and kinematical characteristics of the manipulator. The conventional planar parallel manipulators have some disadvantages which are complex non-closed type direct kinematics, workspaces containing useless voids, and concave type border tines of workspaces. The proposed planar parallel manipulator overcomes the above disadvantages, that is, the manipulator has simple closed type direct kinematics, a void-free workspace, and a convex type borderline of a workspace. This paper shows the simulation result of the workspace as well as performances indices using a homogeneous inverse Jacobian.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.36.3-36
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• 2002

$\textbullet$ Motion capture system $\textbullet$ Exoskeleton mechanism $\textbullet$ Kinematics analysis $\textbullet$ Man-machine Interface $\textbullet$ Wireless communication $\textbullet$ Control algorithm

• 대한의용생체공학회:의공학회지
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• 제29권2호
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• pp.139-145
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• 2008

Many recent studies suggest that the posterior dynamic stabilization(PDS) can be a more physiologically-relevant alternative to the rigid fixation for the patients suffering from low back pain. However, its biomechanical effects or clinically proven efficacies still remain unknown. In this study, we evaluated kinematic behaviors of the lower lumbar spine with the PDS system and then compared to those of the rigid fixation system using finite element (FE) analysis. A validated FE model of intact lumbar spine(L2-L5) was developed. The implanted model was then constructed after modification from the intact to simulate two kinds of pedicle screw systems (PDS and the rigid fixation). Hybrid protocol was used to flex, extend, laterally bend and axially rotate the FE model. Results showed that the PDS systems are more flexible than rigid fixation systems, yet not flexible enough to preserve motion. PDS system allowed $16.2{\sim}42.2%$ more intersegmental rotation than the rigid fixation at the implanted level. One the other hand, at the adjacent level it allowed more range of motion ($2.0%{\sim}8.3%$) than the rigid fixation. The center of rotation of the PDS model remained closer to that of the intact spine. These results suggest that the PDS system could be able to prevent excessive motion at the adjacent levels and restore the spinal kinematics.

• 한국운동역학회지
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• 제33권4호
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• pp.147-154
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• 2023

Objective: This study aimed 1) to compare the Landing Error Scoring System (LESS) score and movement patterns during landing of the lesser dorsiflexion range of motion (LDFROM) group to that with the greater dorsiflexion range of motion group, and 2) to identify the correlation between the weight-bearing dorsiflexion range of motion (WBDF ROM), LESS score, and movement patterns during landing. Method: Fifty health adults participated in this study. WBDF ROM was measured using the weight bearing lunge test while movement patterns during landing was assessed using the LESS. The joint angles of the ankle, knee and hip joints during landing were analyzed using the 2D video analysis. After mean value of WBDF ROM was calculated, participants were divided into two groups (GDFROM and LDFROM) based on the mean value. The Mann-Whiteny 𝒰 test was used to identify differences in movement strategies during landing between two groups and the Pearson's correlation analysis was performed to determine relationships between WBDF ROM and movement strategies. Results: The LDFROM group showed the poorer LESS score and stiffer landing kinematics during landing compared to the GDFROM group (p<0.05). In addition, DFROM was significantly related to the LESS score and landing kinematics (p<0.05) except for total hip excursion (p=0.228). Conclusion: Our main findings showed that the LDFROM group had poorer landing quality and stiffer landing movements compared to the GDFROM group. In addition, increase of WBDF ROM significantly improved landing quality and soft-landing movements. To reduce shock during landing such as ground reaction forces, individuals need to better utilize WBDF ROM and lower extremity movements based on our findings. Therefore, intervention programs for safer landings should include exercises that increase WBDF ROM and utilize eccentric contraction.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.496-499
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• 1997

This paper describes the operating software of a motion system developed for a driving simulator, consisting of a six degree of freedom Stewart platform driven hydraulically. The drive logic, consisting of an washout algorithm, inverse kinematic analysis, and a control algorithm, has been developed and applied for creating high fidelity motion cues. The basic environment of the operating software is based on LabVIEW 4.0 and DLL modules compiled by Fortran.

• 한국운동역학회지
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• 제15권3호
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• pp.1-7
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• 2005

Excessive pronation and impact force during running are related to various running injuries. To prevent these injuries, three type of running shoes are used, such as cushioning, stability, and motion control. Although there were may studies about the effect of midsole hardness on impact force, no study to investigate biomechanical effect of motion control running shoes. The purpose of this study was to determine biomechanical difference between cushioning and motion control shoes during treadmill running. Specifically, plantar and rearfoot motion, impact force and loading rate, and insole pressure distribution were quantified and compared. Twenty male healthy runners experienced at treadmill running participated in this study. When they ran on treadmill at 3.83 m/s. Kinematic data were collected using a Motion Analysis eight video camera system at 240 Hz. Impact force and pressure distribution data under the heel of right foot were collected with a Pedar pressure insole system with 26 sensors at 360 Hz. Mean value of ten consecutive steps was calculated for kinematics and kinetics. A dependent paired t-test was used to compare the running shoes effect (p=0.05). For most kinematics, motion control running shoes reduced the range of rearfoot motion compared to cushioning shoes. Runners wearing motion control shoe showed less eversion angle during standing less inversion angle at heel strike, and slower eversion velocity. For kinetics, cushioning shoes has the effect to reduce impact on foot obviously. Runners wearing cushioning shoes showed less impact force and loading rate, and less peak insole pressure. For both shoes, there was greater load on the medial part of heel compared to lateral part. For pressure distribution, runners with cushioning shoes showed lower, especially on the medial heel.

• 한국운동역학회지
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• 제17권2호
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• pp.51-59
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• 2007

These studies show that I applied to functional insole (a specific A company) for minimizing shocks and sprain people's ankle arising from running. How to an effect on human body which studied a kinematics and kinetics from 10 college students during experiments. This study imposes several conditions by barefoot, normal running shoes and put functional insole shoes ran under average $2.0{\pm}0.24\;m$/sec by motion analysis and ground reaction force that used to specific A company. First of all, motion analysis was caused by achilles tendon angle, angle of the lower leg, angle of the knee, initial sole angle and barefoot angle. The result of comparative analysis can be summarized as below. Motion analysis showed that statically approximates other results from achilles tendon angle (p<.01), initial ankle angle(p<.05), initial sole angle(p<.001) and barefoot angle(p<.001). Ground reaction force also showed that statically approximates other results from impact peak timing (p<.001), Maximum loading rate(p<.001), Maximum loading rate timing (p<.001) and impulse of first 20 percent (p<.001). Above experiment values known that there was statically difference between Motion analysis and Ground reaction force under absorbing of the functional insole shoes which was not have an effect on our body for kinetics and kinematics.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2251-2260
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• 2021

The motion control of the divertor maintenance system of the China Fusion Engineering Test Reactor (CFETR) was studied in this paper, in which CFETR Multi-Functional Maintenance Platform (MFMP) was simplified as a parallel robot for the convenience of theoretical analysis. In order to design the motion controller of parallel robot, the kinematics analysis of parallel robot was carried out. After that, the dynamic modeling of the hydraulic system was built. As the large variation of heavy payload on MFMP and highly nonlinearity of the system, A Fuzzy-PID controller was built for self-tuning PID controller parameters by using Fuzzy system to achieve better performance. In order to test the feasibility of the Fuzzy-PID controller, the simulation model of the system was built in Simulink. The results have showed that Fuzzy-PID controller can significantly reduce the angular error of the moving platform and provide the stable motion for transferring the divertor.