• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.397-397
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• 2000

This paper presents a gait control scheme for teleoperation of a quadruped-walking robot. In teleoperation of a walking robot, an operator gives a real-time generated velocity command to a walking robot instead of a moving trajectory. When the direction of the velocity command is changed, the periodic gait is not available because this requires an initial foot position . This paper proposes the aperiodic gait control scheme that can converge to a periodic gait Simulation results are given to demonstrate the efficiency of the proposed control scheme.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.9
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• pp.959-966
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• 2009

An essential consideration when analyzing the gait of walking robots is their ability to maintain stability during walking. Therefore, this study proposes a vertical waist-jointed walking robot and gait algorithm to increase the gait stability margin while walking on the slope. First, the energy stability margin is compared according to the posture of the walking motion on slope. Next, a vertical waist-jointed walking robot is modeled to analyze the stability margin in given assumption. We describe new parameters, joint angle and position of a vertical waist-joint to get COG (center of gravity of a body) in walking. Finally, we prove the superiority of the proposed gait algorithm using simulation and conclude the results.

• Journal of Biomedical Engineering Research
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• v.26 no.3
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• pp.145-150
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• 2005

A new gait detection system using both FSR (force sensing resistor) sensors and a gyrosensor was developed to detect various gait patterns. FSR sensors were put in self-designed shoe insoles and a gyrosensor was attached to the heel of a shoe. An algorithm was also developed to determine eight different gait transitions during four gait phases: heel-strike, foot-flat, heel-off and swing. The developed system was evaluated from nine heathy mans and twelve hemiplegic patients. Healthy volunteers were asked to walk in various gait patterns: level walking, fore-foot walking and stair walking. Only the level walking was performed in hemiplegic patients. The gait detection system was compared with a optical motion analysis system and the outputs of the FSR sensors. In healthy subjects, the developed system detected successfully more than $99\%$ for both level walking and fore-foot walking. For stair walking, the successful detection rate of the system was above$97\%$. In hemiplegic patients, the developed system detected approximately 98% of gait transitions. The developed gait phase detection system will be helpful not only to determine pathological gait phases but also to apply prosthetics, orthotics and functional electrical stimulation for patients with various gait disorders.

• The Journal of Korean Physical Therapy
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• v.27 no.5
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• pp.364-368
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• 2015

Purpose: Walking in the dual-task condition is a critical skill for hemiplegic patients to live in real-life situations. The purpose of this study was to compare the effect of dual-task gait training and general gait training on gait parameters and cognitive function in patients with chronic stroke during dual-task walking. Methods: The study included 23 patients with chronic hemiparetic stroke who were randomly divided into experimental (dual-task gait training) and control (general walking training) groups. The 11 subjects in the experimental group and nine subjects in the control group received dual-task gait training (walking while handling a ball, crossing obstacles, picking up various objects, and problem solving simple cognitive tasks and general over-ground gait training, respectively, for 30 minutes per day 5 days per week for 4 weeks. Spatiotemporal parameters and cognitive tasks in the dual-task gait condition were measured. Statistical analysis of the changes between the pre- and post-intervention measurement variables was performed using ANCOVA. Results: In the gait condition under cognitive tasks, the changes pre- and post-intervention in gait velocity, stride length, double support limb, and step symmetry were significantly greater in the dual-task gait training group; however, the dual-task gait training group showed no significant improvement compared to the general gait training group in terms of the assessment of cognitive tasks. Conclusion: The findings suggest that dual-task gait training may be beneficial for walking ability in dual-task walking condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.398-402
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• 1996

This paper addresses the design and the gait control of quadruped walking robot. First, we concern the mechanical and electronical(control system) hardware of walking robot, and the second is the results of experiments. The walking robot is the most suitable form to substitute fot human being. So walking robot is worthy of research. The quadruped walking robot and control system is the simplest type of walking robot, therefore we designed a small seale robot for realization of static gait. The robot is designed commpactly and its legs are constructed parallel link type and able to move freely in space. Control system consists of one upper level controller and four lower level controllers. The upper level controller plans the walking path and commands the low level controllers to follow the planned path. The main function of low level cotrollers is control of motors. Total number of motors is twealve and they operate four legs. And robot is ordered to walk and realize static wave gait.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1926-1930
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• 2004

We suggest a turning gait planning of a quadruped walking robot with an articulated spine. Robot developer has tried to implement a gait more similar to that of natural animals with high stability margin. Therefore, so many types of walking robot with reasonable gait have been developed. But there is a big difference with a natural animal walking motion. A key point is the fact that natural animals use their waist-oint(articulated spine) to walk. For example, a crocodile which has short legs relative to a long body uses their waist to walk more quickly and to turn more effectively. The other animals such as tiger, dog and so forth, also use their waist. Therefore, this paper proposes discontinuous turning gait planning for a newly modeled quadruped walking robot with an articulated spine which connects the front and rear parts of the body. Turning gait is very important as same as straight gait. All animals need a turning gait to avoid obstacle or to change walking direction. Turning gait has mainly two types of gaits; circular gait and spinning gait. We apply articulated spine to above two gaits, which shows the majority of an articulated spine more effectively. Firstly, we describe a kinematic relation of a waist-joint, the hip, and the center of gravity of body, and then apply a spinning gait. Next, we apply a waist-joint to a circular gait. We compare a gait stability margin with that of a conventional single rigid body walking robot. Finally, we show the validity of a proposed gait with simulation.

• PNF and Movement
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• v.19 no.2
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• pp.261-267
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• 2021

Purpose: This study aimed to investigate changes in gait variables depending on whether a task was performed using a smartphone while walking on a ramp. Methods: The participants of this study were 41 college students attending U University located in Gyeongju City, Gyeongsangbuk-do. In this study, gait variables were measured during ramp gait while using a smartphone to perform a task and during ramp gait without performing such tasks. In other words, four walking conditions were used: 1) walking up a ramp, 2) walking up a ramp while using a smartphone to perform a task, 3) walking down a ramp, and 4) walking down a ramp while using a smart phone to perform a task. Gait variables were measured using a gait analysis tool (Legsys; BioSensics, USA), and stride time, stride length, stride velocity, cadence, and double support were analyzed. The order of measurements was randomized to control for order effects due to repeated measurements. Results: The comparative analysis of gait variables according to the presence or absence of smartphone use during ramp gait showed that there were significant differences in stride time, stride length, and stride velocity during both ramp ascent and ramp descent (p < 0.05). In both ramp ascent and ramp descent, stride time increased when walking using a smartphone, compared to when walking without using a smartphone (p < 0.05). However, in both ramp ascent and ramp descent, stride length and stride velocity were decreased when walking using a smartphone compared to when walking without using a smartphone (p < 0.05). Conclusion: The study results showed that the use of a smartphone during walking can affect safety. Therefore, it is necessary to improve the awareness of risks associated with walking while using a smartphone, and further research needs to be conducted in various environments and with different ramps.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.8
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• pp.703-710
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• 2004

This paper presents discontinuous zigzag gait analysis for a newly modeled quadruped walking robot with an articulated spine which connects the front and rear parts of the body. An articulated spine walking robot can move easily from side to side, which is an important feature to guarantee a larger gait stability margin than that of a conventional single rigid-body walking robot. First, we suggest a kinematic modeling of an articulated spine robot which has new parameters such as a waist-joint angle, a rotate angle of a front and rear body and describe characteristics of gait using an articulated spine. Next, we compared the difference of walking motion of newly modeled robot with that of a single rigid-body robot and analyzed the gait of an articulated spine robot using new parameters. On the basis of above result, we proposed a best walking motion with maximum stability margin. To show the effectiveness of proposed gait planning by simulation, firstly the fastest walking motion is identified based on the maximum stride, because the longer the stride, the faster the walking speed. Next, the gait stability margin variation of an articulated spine robot is compared according to the allowable waist-joint angle.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.3
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• pp.119-129
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• 2022

Purpose : The purpose of the study was to find out the effects of obstacle walking training according on gait and balance in stroke patients. Methods : Twenty-four stroke patients are randomly assigned to experimental group 1 (n=8), experimental group 2 (n=8) and control group (n=8). Experimental group 1 performed unexpected obstacle walking training, experimental group 2 performed fixed obstacle walking training and control group performed non obstacle walking training for 12 minutes per session, 5 times a week for 4 weeks. The gait analyzer G-walk were evaluated using gait cadence, gait velocity, and stride length, balance was evaluated using FES-K and BBS. Results : In within-group comparison of gait cadence, gait velocity and stride length of change, the experimental 1,2 groups showed significant improvements post intervention (p<.05) but control group showed no significant improvement. In between-groups comparison there was significant difference in the change of gait cadence, gait velocity and stride length pre and post intervention. In within-group comparison of FES-K and BBS scores, the experimental 1,2 groups showed significant improvements post intervention (p<.05) but control group showed no significant improvement. In between-groups comparison there was significant difference in the change of FES-K and BBS scores pre and post intervention (p<.05). Conclusion : Obstacle walking training can improve the gait, function and balance of stroke patients and obstacle walking training is effective for improving gait and balance compared to non-obstacle walking training.

• Korean Journal of Applied Biomechanics
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• v.16 no.2
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• pp.85-95
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• 2006

The purpose of this study of which 10 University students in their twenties are the objects was to examine the causal differences of kinematic and electromyography during power walking and normal gait. We came to the following conclusions. 1) It took less time to stance phase, swing phase and whole gait time during power walking compared with normal gait. 2) During power walking, the step length and step length and lower limb length are longer than that of normal gait. 3) During power walking, ankle joint angle became more plantar flexed at LIC and RTO, knee joint angle become more flexed, so did hip joint angle at LIC and RTO. Besides during power walking the shoulder joint angle movement was bigger and elbow joint angle was more flexed as the trait of power walking. 4) During power walking, through out the phase the muscle activity of all muscle was higher expecially the muscle activity of Biceps brachii, gastrocnemius medialis, gastrocnemius lateralis, Soleus was higher. Therefore during power walking, one's scope of activity and muscle activity is relatively higher than those of normal gait, so power walking helps one strengthen muscular power and energy metabolism. This will be useful information for those who are interested in diet and well-being.