• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.177-185
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• 2014

In this study, the exoskeleton orthosis for the assistance of dorsiflexion torque in ankle joint to prevent foot-drop was developed. It was consist of three part; 1) the power part using artificial pneumatic actuator, 2) wearing part of ankle and knee joints to fix the orthosis, and 3) control part to detect the gait phase using physiological signal. The dorsiflexion torque was generated by the artificial pneumatic actuator connected with wearing part between ankle and knee joint. The accurate timing to assist dorsiflexion torque is made up of physiological signal in foot sole part that detect the gait phase, that is, stance and swing phase in each foot. We conduct the experiment to investigate the effect of exoskeleton orthosis to the 7 elderly people and 10 healthy people. The result showed that the muscular activities in tibialis anterior muscle were reduced because of the assistance of dorsiflexion torque in ankle joint using the exoskeleton orthosis.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.8
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• pp.104-110
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• 2008

The aim of this study ultimately is verifying that PGO gait is more efficient than RGO fur paraplegics because the air muscle assists hip flexion power in heel off movement. The gait characteristics of the paraplegic wearing the PGO or RGO are compared with that of a normal person. PGO with air muscles was used to analyze the walking of patients with lower-limb paralysis, and the results showed that the hip joint flexion and pelvic tilt angle decreased in PGO. In comparison to RGO gait, which is propelled by the movements of the back, PGO uses air muscles, which decreases the movement in the upper limb from a stance phase rate of 79$\pm$4%(RGO) to 68$\pm$8%. The energy consumption rate was 8.65$\pm$3.3 (ml/min/Kg) for RGO, while it decreased to 7.21t2.5(ml/min/Kg) for PGO. The results from this study show that PGO decreases energy consumption while providing support for patients with lower-limb paralysis, and it is helpful in walking for extended times.

• The Journal of Korea Robotics Society
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• v.6 no.1
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• pp.34-41
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• 2011

This paper presents a frequency-response test performed on an antagonistic actuation system consisting of two Mckibben pneumatic artificial muscles and a pneumatic circuit. A linear model, capable of estimating the dynamic characteristics of the antagonistic system in the operating range of pneumatic artificial muscles, was optimally calculated based on frequency-response results and applied to a multiple simultaneous specification control scheme. Trajectory tracking results showed that the presented multiple simultaneous specification controller, built experimentally by three PD typed sample controllers, satisfied successfully all required control specifications; rising time, maximum overshoot, steady-state error.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1704-1707
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• 1997

In this work, position and vibratiion control of a two-link manipulator with one flexible link, which an unkoun but bounded payload mass and two pair of artificial muscle-type penumatic actuators, are investgated. A flexible link robot has advantages over a figid link robot in the sense that it is much safer when it cones into contact with its environment, including humans. Furthermore, for the sake of safety, it would be more desirabel if an actuator could deliver required force while maintaining proper compliance. An artificial muscle-type penumatic actuator is adequate for such cases. In this study, a controller based on singular perturbation method, adaptive and sliding mode contro, and .mu.-synthesis is developed. The effectiveness of the proposed control scheme is confirmed through simulations and experiments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.725-728
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• 2008

An elbow orthosis with a pneumatic rubber actuator has been developed to assist and enhance upper limbs movements and has been examined for the effectiveness. The effectiveness of the elbow orthosis was examined by comparing muscular activities during alternate dumbbell curl motion wearing and not wearing the orthosis. The subjects participated in the experiment were younger adults in their twenties. The subjects were instructed to perform dumbbell curl motion in a sitting position wearing and not wearing orthosis in turn and a dynamometer was used to measure elbow joint torque outputs in an isokinetic mode. Orthosis was controlled using contractile muscle force that is measured from force sensor through cDAQ-9172 board. The air pressure of the pneumatic actuator was 0.3MPa the most suitable air pressure. For the analysis of muscular activities, Electromyography of the subjects was measured during alternate dumbbell curl motion. The experiment results showed that the muscular activities wearing the elbow orthosis were reduced. With this, we confirmed the effectiveness of the developed elbow orthosis.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.10
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• pp.3186-3198
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• 1996

When a robot is to have contact with its enviornment, such as a medi-care robot, it would be advantageous for the robot to have a high compliance. For this reason, a robot having not only a flexible link but also an actuator with compliance, is desirable. This paper is concerned with the position and vibration control of 1 degree of freedom flexible robot using a pneumatic artificial muscle actuator. The dynamics of the manipulator assumed to be and Euler-Bernoulli beam are derived on the basis of the linear mathematical modle. Although this pneumatic artifical muscle actuator has many merits for the compliance robot, it is difficult to make an effective control scheme of this system because of ths nonlinearity and uncertainty on the dynamics of the actuator. By designing a controller using .mu.-synthesis, robust performance against measurement noise, various modeling uncertainties on the dynamics of the servo valve, actuator and mainpulator, is achieved. The effectiveness of the proposed control method is illustrated through simulations and experiments.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.6
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• pp.82-89
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• 2010

Ankle-foot orthosis with an artificial pneumatic muscle which is intended for the assistance of plantarfelxion torque was developed. In this study, power pattern of the device in the various pneumatics and the effectiveness of the system were investigated. The pneumatic power was provided by ankle-foot orthosis controlled by user‘s physiological signal, that is, muscular stiffness in soleus muscle. This pneumatic power can assist plantarflexion torque of ankle joint. The subjects performed maximal voluntary isokinetic plantarflexion motion on a biodexdynamometer in different pneumatics, and they completed three conditions: 1) without wearing the orthosis, 2) wearing the orthosis with artificial muscles turned off, 3) wearing the orthosis activated under muscular stiffness control. Through these experiments, we confirmed the effectiveness of the orthosis and muscular stiffness control using the analyzing isokinetic plantarflexion torque. The experimental results showed that isokinetic torques of plantarflexion motion of the ankle joints gradually increased in incremental pneumatic. The effectiveness of the orthosis was -7.26% and the effectiveness of the muscular stiffness control was 17.83% in normalized isokinetic plantarflexion torque. Subjects generated the less isokinetic torques of the ankle joints in wearing the orthosis with artificial muscles turned off, but isokinetic torques were appropriately reinforced in condition of wearing the orthosis activated under muscular stiffness control(17.83%) compared to wearing the orthosis(-7.26%). Therefore, we respect that developed powered orthosis is applied in the elderly that has weak muscular power as the rehabilitation equipment.