• 한국정밀공학회지
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• 제28권6호
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• pp.687-693
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• 2011

Spring-mass models have been widely accepted to explain the basic dynamics of human gait. Researchers found that the leg stiffness increased with gait speed to increase energy efficiency. However, the difference of leg stiffness change with gait speed between the young and the elderly has not been verified yet. In this study, we calculated the lower limb stiffness of the elderly using walking model with an axial spring. Vertical stiffness was defined as the ratio of the vertical force change to the vertical displacement change. Seven young and eight elderly subjects participated to the test. The subjects walked on a 12 meter long, 1 meter wide walkway at four different gait speeds, ranging from their self-selected speed to maximum speed randomly. Kinetic and kinematic data were collected using three force plates and motion capture cameras, respectively. The vertical stiffness of the two groups increased as a function of walking speed. Maximum walking speed of the elderly was slower than that of the young, yet the walking speed correlated well with the optimal stiffness that maximizes propulsion energy in both groups. The results may imply that human may use apparent limb stiffness to optimize energy based on spring-like leg mechanics.

• 제어로봇시스템학회논문지
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• 제17권10호
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• pp.1029-1036
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• 2011

An energy-efficient reference walking trajectory generation algorithm is suggested utilizing allowable ZMP (Zero-Moment-Point) region, which maxmizes the energy efficiency for cyclic gaits, based on three-dimensional LIPM (Linear Inverted Pendulum Model) for biped robots. As observed in natural human walking, variable ZMP manipulation is suggested, in which ZMP moves within the allowable region to reduce the joint stress (i.e., rapid acceleration and deceleration of body), and hence to reduce the consumed energy. In addition, opimization of footstep planning is conducted to decide the optimal step-length and body height for a given forward mean velocity to minimize a suitable energy performance - amount of energy required to carry a unit weight a unit distance. In this planning, in order to ensure physically realizable walking trajectory, we also considered geometrical constraints, ZMP stability condition, friction constraint, and yawing moment constraint. Simulations are performed with a 12-DOF 3D biped robot model to verify the effectiveness of the proposed method.

• Spatial Information Research
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• 제19권1호
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• pp.83-91
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• 2011

The route finding analysis is an essential geo-related decision support tool in a LBS(Location based Services) and previous researches related to route guidance have been mainly focused on route guidances for vehicles. However, due to the recent spread of personal computing devices such as PDA, PMP and smart phone, route guidance for pedestrians have been increasingly in demand. The pedestrian route guidance is different from vehicle route guidance because pedestrians are affected more surrounding environment than vehicles. Therefore, pedestrian path finding needs considerations of factors affecting walking. This paper aimed to extract factors affecting walking and charting the factors for application factors affecting walking to pedestrian path finding. In this paper, we found various factors about environment of road for pedestrian and extract the factors affecting walking. Factors affecting walking consist of 4 categories traffic, sidewalk, network, safety facility. We calculated weights about each factor using analytic hierarchy process (AHP). Based on weights we calculated scores about each factor's attribute. The weight is maximum score of factor. These scores of factor are used to optimal pedestrian path finding as path finding cost with distance, accessibility.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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• pp.402-408
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• 2003

Now many major airports in the world which operate strategic alliance or Hub & Spoke system have met capacity restriction and confusion problems. And the time and the walking distance for boarding to flight are important standard to measure customer convenience. And the effective gate assignment guarantees customers convenience as well as increasing airport capacity without expanding established airport equipments. So it can be a major concern to manage airports. So this paper formulate gate assignment problem in the hub airport not quadratic assignment problem but a improved single-period integer problem which is minimize local and transit passengers I walking distance. As a result, this study will present a method producing optimal gate assignment result using optimization software. We use real flights and gates data in the national airport, so we will compare a assignment results with a real airport assignment results and previous researches and analyze those results.

• 재활복지공학회논문지
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• 제5권1호
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• pp.17-25
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• 2011

본 논문은 전동 보행보조기의 편의성 향상을 위한 최적의 제어 이득을 찾고 제어 알고리즘을 설계하였다. 최근 노인의 인구가 의료 기술의 발달로 급속히 증가되고 있으며, 다양한 이동형 보행보조기구는 삶의 질을 개선하기 위해 개발되고 있다. 이러한 이동형 제품 중 수동형 보행보조기는 노인의 보행의 힘을 도와주는 전동모터를 가지고 있지 않아 노인들이 충분한 근력이 없기 때문에 경사로 및 문의 문턱 등 고르지 않는 지형에서 이동하는데 제안사항이 있다. 이러한 상황을 극복하기 위해 전동타입의 보행보조기를 개발하였다. 전동형 보행보조기는 수동형과 다르게 사용자가 조작을 해야 모터가 구동되는 구조이다. 이러한 구조는 사용자가 조작을 잘못 하였을 경우 상당한 불편함을 사용자에게 준다. 이러한 전동형 보행보조기를 수동형 보행보조기와 비교하여 조작의 편의성을 판단하고 기준을 만들어 사용자의 편의성에 대하여 제어 값을 변경하면서 사용자 편의성을 개선하였다. 본 논문에서는 보행의지를 인식하고 편의성의 성능을 측정할 수 있는 방법인 햅틱 센서를 소개하며 편의를 개선하는 제어 알고리즘을 제안한다. 또한 편의성의 평가는 COV(Center of Vehicle)와 사용자의 COP(Center of Position)과의 차이의 변화를 통해 상대적인 편의성을 평가하였다. 전동 타입 보행보조기와 새로운 측정방법을 도입하여 모든 과정을 실험을 통하여 확인 하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.315-318
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• 1995

In this paper, an optimal trunk trajectory for stable walking of biped robots is expressed as a simple differential equation, which is then solved by numerical methods. We used ZMP (Zero Moment Point), the virtual total ground reaction point within the region of the supporting food, as the criterion of stability of biped robot walking. If the ZMP is located outside of the stable region in dynamic walking, biped robots fall down. The biped robot considered in this paper consists of two legs and a trunk. The trajectories of the two legs and the ZMP of the biped robot are determined such that they are similar ti those of a human. Based upon those trajectories, the trunk trajectory is solved by numerically integrating differential dynamic equations. Leg motions are controlled by the computed torque control method. The effectiveness of control algorithm as well as the trajectories is confirmed by computer simulations.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2004년도 춘계학술대회 학술발표 논문집 제14권 제1호
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• pp.277-280
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• 2004

In the research of biomechanical engineering, robotics and neurophysiology, to clarify the mechanism of human bipedal walking is of major interest. It serves as a basis of developing several applications such as rehabilitation tools and humanoid robots Nevertheless, because of complexity of the neuronal system that Interacts with the body dynamics system to make walking movements, much is left unknown about the details of locomotion mechanism. Researchers were looking for the optimal model of the neuronal system by trials and errors. In this paper, we applied Genetic Programming to induce the model of the nervous system automatically and showed its effectiveness by simulating a human bipedal walking with the obtained model.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.523-528
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• 2000

In this paper, the new type biped walking robot which is composed of the minimum number or links just for walking and its appropriate gaits are proposed. The proposed new gaits for this robot are four-crossing, crawling, standing and turning gait. In designing the biped robot we propose the Performance Index which means the needed torque per a moving distance and generate foot trajectories by $3^{rd}$ order spline Interpolation. Among those, numerically we find the optimal conditions which minimize the Performance Index. Dynamically stable walking of the biped robot is realized by satisfying the stability condition of ZMP(zero moment point), which is related to maintaining the ZMP within the region of the supporting foot during the s1n91e leg support phase. We determine the region of mass center from the stability condition of ZMP and plan references which track the mass conte. trajectory of constant velocity. Finally we implement the gaits statically tracking the planned trajectories using PD control method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2405-2407
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• 2003

This study deals with the gait optimization of via points on biped robot. ZMP(Zero Moment Point) is most important index in a biped robot's dynamic walking stability. To stable walking of a biped robot, legs's trajectory and a desired ZMP trajectory is required, balancing weight's movement is solved by FDM(Finite Difference Method). In this study, optimal index is defined to dynamically static walking of a biped robot, and optimization of via points is applied by GA(Genetic Algorithm).

• 한국전기전자재료학회논문지
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• 제33권5호
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• pp.380-385
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• 2020

Over the past decade, small robots have been of particular interest in the engineering field. Among the various types of small robots, biomimetic robots, which mimic animals and insects, have been developed for special activities in areas where humans cannot physically access. The optimal motion of a walking robot can be determined by the characteristics of the traversed surface (e.g., roughness, curvature, slope, materials, etc.). This study proposes three types of piezoelectric structures using different driving mechanisms, depending on the application range of the small walking robots. Dynamic modeling using computer-aided engineering optimized the shape of the robot to maximize its moving characteristics, and the results were also verified through its fabrication and experimentation. Three types of robots, named by their actuator shapes as I, π, & T-shape, were proposed regarding application for small scale ambulatory robots to different terrain conditions. Among these, the T-shaped robots were shown to have a wide range of speeds (from 2 mm/s up to 255 mm/s) and good carrying capacity (up to 10 g at 50 mm/s) through driving experiments. Based on this study, we proposed possible application areas for the three types of walking robot actuators.