• Title/Summary/Keyword: power assist

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Development of Usability Evaluation Criteria for Senior-Friendly Autonomous Transportation Robot

  • Kim, Seon Chil;Kim, Sun Jung;Choi, Kyongon
    • Journal of the Ergonomics Society of Korea
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    • v.33 no.5
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    • pp.407-422
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    • 2014
  • Objective: The purpose of the study is to develop quantitative usability evaluation criteria for senior-friendly autonomous transportation robot. Background: The Republic of Korea has become the most rapidly aging society, and is anticipated to enter the post-aged society in 2026. To raise the quality of life of a senior with limited mobility and to reduce the burden of caregivers, many high-tech assistive products with information technologies are developed nowadays. The senior-friendly autonomous transportation robot is one person robot vehicle to move a senior to the destination for hospitals, nursing homes or silver town complex. With built-in navigation system and environmental monitoring censors, it automatically seeks the path to the destination and avoids collision to obstacles and pedestrians on the way. Due to the early stage of the product, few usability studies in this field have been done, mostly on general service robots to assist seniors, power wheelchairs and delivery robots. ISO and KS standards for the service robots are focused on safety. Method: Based on the reference usability index, the early draft of the usability evaluation questionnaires was developed. After small group tests and interviews, the experts modified the initial draft to the Usability Evaluation Criteria for Senior-Friendly Autonomous Transportation Robot (UEC-SFATR). Result: UEC-SFATR consisted of 4 subscales - Safety, Controllability, Efficiency and Satisfaction. All of the 4 subscales of UEC-SFATR were passed the reliability criteria by 4 groups of seniors, divided by gender and familiarity of smart-devices. Conclusion: UEC-SFATR covers wider area of user experiences of the SFATR and is a good measurement tool to help both the users and developers of the robot. Application: This study provides guide to the future product development and product competitiveness evaluation by quantifying user experiences for the SFATR.

Evaluating Carbon Dioxide Emission from Cadastral Category based on Tier 3 Approach (Tier 3 방식에 의거한 지목별 온실가스 배출 실태평가)

  • Kim, Dae-Ho;Um, Jung-Sup
    • Spatial Information Research
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    • v.19 no.3
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    • pp.11-22
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    • 2011
  • It is usual for the carbon dioxide emission to be calculated by official energy consumption statistics produced from a number of specialized industrial process such as refinery, power plant etc. The aim of this research was to evaluate potential of cadastral system in monitoring carbon dioxide emitted from land use. An empirical study for a cadastral category was conducted to demonstrate how a on-site measurement can be used to assist in estimating the carbon dioxide emission in terms of land use specific settings. The cadastral category based analysis made it possible to identify area-wide patterns of carbon dioxide emission, which cannot be acquired by traditional Government statistics. It was possible to identify successively increasing trends in the human-related parcels such as housing land while decreasing trends of carbon dioxide in sink parcels(eg. forest). The results indicate that the cadastral parcel could be used not only as a tool to monitor carbon dioxide emission, but also as an evidence to restrict initiation of development activities causing negative influence to carbon dioxide emission such as road construction. As a result, the research findings have established the new concept of "carbon dioxide emission monitoring based on cadastral category", proposed as an initial aim of this paper.

A study on the animal figures in Scytian Ornament -focusing on the single animal figures (스카타이계 장식품에 나타난 동물문에 대한 연구 -단독동물문을 중심으로-)

  • 김문자
    • Journal of the Korean Home Economics Association
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    • v.38 no.8
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    • pp.13-27
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    • 2000
  • The background of single animal figures was originated from those northern mounted nomadic groups, which was Scythe style Culture. The art of the nomads working in the Scythian idiom was small in size and essentially decorative in intention, yet practically every object which can be associated with any unit in this group of people possesses many of the attributes essential to a real work of art. Clarity of conception, purity of form, co-ordination of rhythm and balance, and not least, an understanding and respect for the material employed were triumphantly blended by the Eurasian nomads to produce a distinctive style. In Scythian art the multitude of animal representations well illustrates the reoccupation of this nomadic people with animals in their environment. Usually only wild animals are represented. Commonly depicted are: stags and deer, lions or other large cats, eagles, birds heads (perhaps of ravens), griffins, snakes, hares, fish, goats, rams, boars, moose (elk), yak, sheep and bears. The occasional exception to the wild animal rule is domesticated horses-important because the Scythians were horse bleeders and their whole culture revolved around their dependence on the horse. The nomads had little reason to create object in honour of gods or men, but they had an instinct for beauty and the wish to surround themselves with the animal forms in which they had come to delight The Scytians tried to combine in a single rendering all the salient points of the animal they were delineating. They archived considerable success in the difficult task of showing in a single image the various and often incompatible poses assumed by a single animal in the course of its life. Zoomorphic motifs were used not simple for decorative effect, but to trim the object into amulets, with magical power to assist in hunting, and to protect the owner from harm.

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Operator Modeling and Design of Fuzzy Controller for a Wire-Driven Heavy Material Lifting System (와이어 구동식 중량물 권양 시스템을 위한 퍼지제어기 설계 및 작업자 모델링)

  • Song, Bo-Wei;Seo, Hyun-Duk;Lee, Yun-Jung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.23 no.5
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    • pp.436-443
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    • 2013
  • This paper presents design methods of a fuzzy controller and an operator model for a wire-driven heavy material lifting system helping human workers. The wire-driven heavy material lifting system is a kind of human-assistive systems in which a human is involved in the control loop. Thus, human's control characteristics and requirement of reducing worker's force to lift a heavy material are considered in the design process of the proposed fuzzy controller. An automatic weight measurement algorithm during the early stage of lifting is also introduced. Finally, the effectiveness and performance of the proposed system are proved by experiments.

The Effect of Motivation for Major Choice and Satisfaction in Major on the Adaption of university Life among university students (대학생의 전공선택 동기 및 전공만족도가 대학생활 적응에 미치는 영향)

  • Park, An-Sook;Kim, Hey-Kyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.2
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    • pp.511-519
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    • 2016
  • The purpose of this study was to examine the effects of motivation for the selection of major and satisfaction in the major on the adaption of university life among university students and to present basic data to assist in the healthy adaption of university life. A survey was given to university students in Seoul and Chungcheong cities from October 13 to October 27, 2015 of 250 copies of the questionnaire distributed, a total of 242 copies were in the final analysis. For data analysis, SPSS 21.0 for Windows was used. As a result, there were correlations among the variables, the adaption of University life of university students was affected by the personal motivation, social motivation for the selection of major with the largest effect being class satisfaction. The explanatory power was 38%. In conclusion, it is important to develop teaching and learning programs and counselling students considering class satisfaction for improving the adaption to university life.

Development of a Prototype of Guidance System for Rice-transplanter

  • Zhang, Fang-Ming;Shin, Beom-Soo;Feng, Xi-Ming;Li, Yuan;Shou, Ru-Jiang
    • Journal of Biosystems Engineering
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    • v.38 no.4
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    • pp.255-263
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    • 2013
  • Purpose: It is not easy to drive a rice-transplanter avoiding underlapped or overlapped transplanting in paddy fields. An automated guidance system for the riding-type rice-transplanter would be necessary to operate the rice-transplanter autonomously or to assist the beginning drivers as a driving aid. Methods: A prototype of guidance system was composed of embedded computers, RTK-GPS, and a power-steering mechanism. Two Kalman filters were adopted to overcome sparse positioning data (1 Hz) from the RTK-GPS. A global Kalman filter estimated the posture of rice-transplanter every one second, and a local Kalman filter calculated the posture from every new estimation of the global Kalman filter with an interval of 200 ms. A PID controller was applied to the row-following mode control. A control method of U-turning mode was developed as well. A stepping motor with a reduction gear set was used to rotate the shaft of steering wheel. Results: Test trials for U-turning and row-following modes were done in a paddy field after some parameters have been tuned at the ground speed range of 0.3 ~ 1.2 m/s. The minimum RMS error of offset was 3.13 cm at the ground speed of 0.3 m/s while the maximum RMS error was 13.01 cm at 1.2 m/s. The offset RMS error tended to increase as the ground speed increased. The target point distance, LT also affected the system performance and PID controller parameters should be adjusted on different ground speeds. Conclusions: A target angle-based PID controller plus stationary steering angle controller made it possible for the rice-transplanter to steer autonomously by following a reference line accurately and even on U-turning mode. However, as condition in paddy fields is very complicated, the system should control the ground speed that prevents it from deviating too much due to ditch and slope.

Theoretical Design for the Production of Quinoa (Chenopodium quinoa Willd.) in a Closed Plant Factory

  • Bae, Jong Hyang;Austin, Jirapa;Jeon, Yoon-A;Cha, Mi-Kyung;Cho, Young-Yeol
    • Horticultural Science & Technology
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    • v.34 no.6
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    • pp.840-844
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    • 2016
  • Quinoa (Chenopodium quinoa Willd.) is a grain crop with high nutritional value. The leaves and sprouts of quinoa can also be consumed either raw or cooked, providing considerably nutritional value as well as high antioxidant and anticancer activities. This study was carried out to obtain basic data to assist in the practical design of a plant factory with artificial lighting for the cultivation of quinoa as a leafy vegetable. We estimated the energy content of the quinoa and the electrical energy required to produce this crop. The yield was 1,000 plants per day, with a planting density and light intensity of $0.015m^2$ ($15{\times}10cm$) and $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The total number of plants, cultivation area, and electricity consumption were estimated to be 25,000, $375m^2$, and $93,750{\mu}mol{\cdot}s^{-1}$, respectively. White fluorescent lamps were used at a power of 20.4 kW from 1,857 fluorescent lamps (FL, 55 W), and the cost for electricity was approximately 1,820 dollars (exchange rate of $1 = 1,200 won) per month. For a daily harvest of 1,000 plants per day in a closed plant factory, the estimated light installation cost, total installation cost, and total production cost would be 15,473, 46,421, and 55,704 dollars, respectively. The calculated production cost per plant, including labor costs, would be 27 cents for the 25-day cultivation period, with a marketable ratio of 80%. Considering the annual total expenses, income, and depreciation costs, the selling price per plant was estimated to be approximately 56 cents.

A Medium Access Control Mechanism for Distributed In-band Full-Duplex Wireless Networks

  • Zuo, Haiwei;Sun, Yanjing;Li, Song;Ni, Qiang;Wang, Xiaolin;Zhang, Xiaoguang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.11
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    • pp.5338-5359
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    • 2017
  • In-band full-duplex (IBFD) wireless communication supports symmetric dual transmission between two nodes and asymmetric dual transmission among three nodes, which allows improved throughput for distributed IBFD wireless networks. However, inter-node interference (INI) can affect desired packet reception in the downlink of three-node topology. The current Half-duplex (HD) medium access control (MAC) mechanism RTS/CTS is unable to establish an asymmetric dual link and consequently to suppress INI. In this paper, we propose a medium access control mechanism for use in distributed IBFD wireless networks, FD-DMAC (Full-Duplex Distributed MAC). In this approach, communication nodes only require single channel access to establish symmetric or asymmetric dual link, and we fully consider the two transmission modes of asymmetric dual link. Through FD-DMAC medium access, the neighbors of communication nodes can clearly know network transmission status, which will provide other opportunities of asymmetric IBFD dual communication and solve hidden node problem. Additionally, we leverage FD-DMAC to transmit received power information. This approach can assist communication nodes to adjust transmit powers and suppress INI. Finally, we give a theoretical analysis of network performance using a discrete-time Markov model. The numerical results show that FD-DMAC achieves a significant improvement over RTS/CTS in terms of throughput and delay.

Effect of Exoskeleton Orthosis for Assistance of Dorsiflexion Torque in Walking Pattern and Lower-limb Muscle (족배굴곡 보조용 외골격 보조기가 보행자의 보행패턴 및 하지근육에 미치는 효과)

  • Oh, H.J.;Kim, K.;Jeong, G.Y.;Jeong, H.C.;Kwon, T.K.
    • 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.

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Development of a coordinated control algorithm using steering torque overlay and differential braking for rear-side collision avoidance (측후방 충돌 회피를 위한 조향 보조 토크 및 차등 제동 분배 제어 알고리즘 개발)

  • Lee, Junyung;Kim, Dongwook;Yi, Kyongsu;Yoo, Hyunjae;Chong, Hyokjin;Ko, Bongchul
    • Journal of Auto-vehicle Safety Association
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    • v.5 no.2
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    • pp.24-31
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    • 2013
  • This paper describes a coordinated control algorithm for rear-side collision avoidance. In order to assist driver actively and increase driver's safety, the proposed coordinated control algorithm is designed to combine lateral control using a steering torque overlay by Motor Driven Power Steering (MDPS) and differential braking by Vehicle Stability Control (VSC). The main objective of a combined control strategy is twofold. The one is to prevent the collision between the subject vehicle and approaching vehicle in the adjacent lanes. The other is to limit actuator's control inputs and vehicle dynamics to safe values for the assurance of the driver's comfort. In order to achieve these goals, the Lyapunov theory and LMI optimization methods has been employed. The proposed coordinated control algorithm for rear-side collision avoidance has been evaluated via simulation using CarSim and MATLAB/Simulink.