• The Journal of Korea Robotics Society
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• v.15 no.4
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• pp.323-329
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• 2020

This paper presents a control algorithm for a wearable walking aid robot for subjects with paraplegia after stroke. After a stroke, a slow, asymmetrical and unstable gait pattern is observed in a number of patients. In many cases, one leg can move in a relatively normal pattern, while the other leg is dysfunctional due to paralysis. We have adopted the so-called assist-as-needed control that encourages the patient to walk as much as possible while the robot assists as necessary to create the gait motion of the paralyzed leg. A virtual wall was implemented for the assist-as-needed control. A position based admittance controller was applied in the swing phase to follow human intentions for both the normal and paralyzed legs. A position controller was applied in the stance phase for both legs. A power controller was applied to obtain stable performance in that the output power of the system was delimited during the sample interval. In order to verify the proposed control algorithm, we performed a simulation with 1-DOF leg models. The preliminary results have shown that the control algorithm can follow human intentions during the swing phase by providing as much assistance as needed. In addition, the virtual wall effectively guided the paralyzed leg with stable force display.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.3
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• pp.239-242
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• 2015

In this paper, we propose a walking assisting system for blind people using Android smartphone and Arduino board. In our proposed system, we use an Android smartphone case and an external ultrasonic sensor to detect the obstacles ahead. In this manner, blind people is able to aware unexpected objects by smartphone speakers or vibration functionality. In addition, the walking assisting system is also designed a notice system which will be triggered by built-in smartphone camera flash when blind people walk in some darkness place. The experimental results from real experiments on blind people have demonstrated the applicability of our walking assisting system, when it not only efficiently helps blind people avoid obstacles ahead but also possible traffic collisions in darkness condition.

• Journal of Biomedical Engineering Research
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• v.31 no.4
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• pp.269-274
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• 2010

The purpose of this study was to develop the FSR sensor suit that controls walking assist device for paraplegic patients. The FSR sensor suit was to detect user's intent and patterns for walking by measuring pressure on the palm and the sole of user's foot. It consisted of four modules: sensing pressure from palm, changing modes and detecting pressure on the palm/at the wrist, sensing pressure from the soles of user's foot, and host module that transmit FSR data obtained from sensing modules to PC. Sensing modules were connected to sensing pads which detect analog signals obtained from the palm or the sole of foot. These collect signals from the target regions, convert analog signals into digital signals, and transmit the final signals to host module via zigbee modules. Finally, host modules transmit the signals to host PC via zigbee modules. The study findings showed that forces measured at the palm when using a stick reflected user's intent to walk and forces at the sole of the user's foot revealed signals detecting walking state.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.46-51
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• 2004

This paper presents an adaptive control method based on parameter linearization for incompletely restrained wire-suspended mechanisms. The main purpose of this control method is utilizing it in a walking assist service robot for elderly people. This method is computationally simple and requires neither end-effector acceleration feedback nor inversion of estimated inertia matrix. In the proposed adaptive control law, mass, moment of inertia and external force and torque on the end-effector are considered as components of parameter adaptation vector. Nonlinear simulation for walking an elderly shows the effectiveness of the parameter adaptation law.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.435-436
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• 2013

• International conference on construction engineering and project management
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• 2022.06a
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• pp.863-870
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• 2022

Unsatisfactory urban walking environment stresses urban residents, and may cause mental illness and chronic diseases by reducing walking activities. Therefore, establishing a high-quality walking environment that can promote walking activities in urban residents has emerged as an important issue. The walking environment consists of various components, such as trees, stairs, streetlights, benches, signs, fences, and facilities, and it is essential to understand which components and their settings act as satisfiers or dissatisfiers for pedestrians, to create a better quality walking environment. Therefore, this study investigated pedestrian satisfaction and dissatisfaction as a function of various environmental components through a survey using walking environment images. The results revealed that most of the walking environment components except the braille block and treezone exhibited significant correlations with pedestrian satisfaction. Particularly, safety-related component (e.g., adjacent roads, parked cars, traffic cushions, and car separation), and landscape-related components (e.g., trees and green), as well as the material settings of landscape facilities (e.g., wooden fences, benches, stairs, and walkway surfaces) correlated with pedestrian satisfaction. The results of this study can contribute to the extraction of useful features to evaluate pedestrian satisfaction as a function of the walking environment. The research outcome is expected to assist in the effective arrangement of walking environment components and their settings, which will ultimately contribute to significantly satisfactory walking environment and encourage walking activities.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.3
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• pp.323-330
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• 2010

Purpose : The purpose of this study was to evaluate the effects of muscle activation of neck, lumbar and low limb by using baby carrier with arms during walking. Methods : Twenty healthy and young females who brought up infants and had no musculoskeletal disorders of neck, lumbar and low limb were recruited for this study. They were instructed to perform muscle activation of neck, lumbar and low limb using the baby carrier with and without arms during walking. ProComp $infiniti^{TM}$ (Thought Technology Ltd., Canada) was used to measure the muscle activity of neck, lumbar and lower extremity muscles. Results : Activation of neck paraspinalis muscle was significantly increased using baby carrier with arms and there was a significant increase on erector spinae muscle activation by using anterior baby carrier. Conclusion : These results indicate that the muscle activation was changed by arms assist and the position of using baby carrier. Therefore, it could be considered relationship of muscle activation and musculoskeletal demage as carrying baby.

• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.320-328
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• 2021

As the number of visually impaired people steadily increases, interest in independent walking is also increasing. However, there are various inconveniences in the independent walking of the visually impaired at present, reducing the quality of life of the visually impaired. The white cane, which is an existing walking aid for the visually impaired, has difficulty in recognizing upper obstacles and obstacles outside the effective distance. In addition, it is inconvenient to cross the street because the sound signal to help the visually impaired cross the crosswalk is lacking or damaged. These factors make it difficult for the visually impaired to walk independently. Therefore, we propose the design of an embedded system that provides traffic light recognition through object recognition technology, voice guidance using TTS, and upper obstacle recognition through ultrasonic sensors so that blind people can realize safe and high-quality independent walking.

• The Journal of Korea Robotics Society
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• v.18 no.4
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• pp.481-486
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• 2023

The purpose of this study is to optimize parameters of a contact model to obtain similar ground contact force of human walking. Dynamic walking simulation considering ground contact is performed to determine load specifications when developing walking assist robots. Large contact forces that are not observed in actual experimental data occur during the simulation at the initial contact (e.g., heel contact). The large contact force generates unrealistic large joint torques. A lower exoskeleton robot with no ankles is developed with the Matlab simscape and the nonlinear hyper volumetric contact model is applied. Parameters of the nonlinear hyper volumetric model were optimized using actual walking contact force data. As a result of optimization, it was possible to obtain a contact force pattern similar to actual walking by removing the large contact force generated during initial contact.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.591-597
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• 2022

Objective: The sitting and standing are motions that correspond to the previous stage of rehabilitation to go to walking for daily life. The purpose of this study was to measure task times, path length of the center of pressure (COP) and activity on the vastus femoris muscle using surface electromyography (EMG) when standing up and sitting down. Design: One group cross-sectional design Methods: Fifteen elderly subjects (8 male, 7 female) participated. All subjects were tested three times according to four assist levels (non-assist, lower, middle, and maximal assist) using adjusts the length of spring at sit-to-stand and stand to sit on a chair. The task duration, and COP path length were recorded for the balance function on the Nintendo Wii fit board. The activity of the rectus femoris muscle was recorded on both legs using surface EMG. Results: The results showed that the task duration of the sit-to-stand and stand-to-sit were significantly increased compared to without assist (p<.05). The activation of the rectus femoris muscle more significantly decreased compared to without assistance at standing or sitting (p<.05). Conclusions: The assistive chair showed less quadriceps muscle activation during sitting and standing compared to without assistance. We suggest that our assist-standing chair can help with activities of daily living such as standing up and sitting down movements adjusting the spring length for control assist level by safely.