• 한국정보과학회논문지:소프트웨어및응용
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• 제26권1호
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• pp.157-157
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• 1999

Researches on the gesture recognition have become a very interesting topic in the computer vision area, Gesture recognition from visual images has a number of potential applicationssuch as HCI (Human Computer Interaction), VR(Virtual Reality), machine vision. To overcome thetechnical barriers in visual processing, conventional approaches have employed cumbersome devicessuch as datagloves or color marked gloves. In this research, we capture gesture images without usingexternal devices and generate a gesture trajectery composed of point-tokens. The trajectory Is spottedusing phase-based velocity constraints and recognized using the discrete left-right HMM. Inputvectors to the HMM are obtained by using the LBG clustering algorithm on a polar-coordinate spacewhere point-tokens on the Cartesian space .are converted. A gesture vocabulary is composed oftwenty-two dynamic hand gestures for editing drawing elements. In our experiment, one hundred dataper gesture are collected from twenty persons, Fifty data are used for training and another fifty datafor recognition experiment. The recognition result shows about 95% recognition rate and also thepossibility that these results can be applied to several potential systems operated by gestures. Thedeveloped system is running in real time for editing basic graphic primitives in the hardwareenvironments of a Pentium-pro (200 MHz), a Matrox Meteor graphic board and a CCD camera, anda Window95 and Visual C++ software environment.

• 한국정밀공학회지
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• 제21권1호
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• pp.101-108
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• 2004

An electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to obtain stable control performance. In this report, we applied disturbance estimation and compensation type robust control to all axes in a 3-link electro-hydraulic manipulator. From the results of experiment, it was confirmed that the performance of trajectory tracking and attitude regulating is greatly improved by the disturbance observer, which model is the same for each axis. On the other hand, for the autonomous assembly tasks, it is said that compliance control is one of the most available methods. Therefore we proposed compliance control which is based on the position control by disturbance observer for our manipulator system. To realize more stable contact work, the states in the compliance loop are feedback, where not only displacement but also velocity and acceleration are considered. And we applied this compliance control to Peg-in-Hole insertion task and analyzed mechanical relation between peg and hole. Also we proposed new method of shifting the position of end-effector periodically for the purpose of smooth insertion. As a result of using this method, it is experimentally confirmed that Peg-in-Hole insertion task with a clearance of 0.05［mm］can be achieved.

• 멤브레인
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• 제24권5호
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• pp.341-349
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• 2014

분자 동력학(Molecular dynamics; MD) 전산모사 기술은 대상이 되는 입자(일반적으로, 원자)의 위치와 속도를 계산하여, 원자 및 분자들의 다양한 구조 및 동적 특성을 분석하는 데에 있어서 매우 유용한 기술이다. 기체 분리막 연구에 있어서도 MD는 그동안 free volume 분석, conformation search 등과 같은 고분자 구조 분석 및 permeability, diffusivity와 같은 기체 투과 거동을 연구하는 데 널리 사용되어 왔다. 본 총설에서는 기체 분리막 분야에 MD를 적용하는 일반적인 방법론에 대하여 서술하고, 다양한 관련 연구들을 소개하고자 한다.

• 제어로봇시스템학회논문지
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• 제6권2호
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• pp.190-196
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• 2000

A hybrid position/force control scheme to regulate the force and position by dual arms is proposed where two arms are treated as one rm in a kinematic viewpoint. The force error calculated from the information of two force/torque sensors attached to the end of each arm is transferred to minimum configuration space coordinates and then is distributed to total system joint coordinates, The position adjustment at the total con-figuration coordinates is computed based on the effective compliance matrix with respect to total joint coordinates which is obtained by coordinate transformation between the task coordinates and the total joint coordinates. The proposed scheme is applied to sawing task. When the trajectory of the saw is planned to follow a line in a horizontal plane 2 position parameters are to be controlled(i.e., two translational positions) Also a certain level of contact force has to be controlled along the vertical direction(i.e. minus z-direction) not to loose the contact with the object to be sawn. We experimentally show that the performance of the velocity and force response are satisfactory. The proposed hybrid control scheme can be applied to arbitrary two cooperating arm system regardless of their kinematic structure and the number of actuated joints.

• 한국항공우주학회지
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• 제38권9호
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• pp.907-913
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• 2010

본 논문에서는 공군에서 운용중인 전투기를 활용한 비행시험 수행 시 비행자료를 얻기 위한 외장형 계측시스템 개발에 대하여 서술하였다. 전투기의 외장형 계측시스템은 계측 포드와 영상 포드로 구성된다. 계측 포드는 GPS/AHRS 센서를 이용하여 전투기 비행자세, 속도 및 고도 등의 비행자료를 측정하며, 영상 포드는 2대의 고속카메라와 1대의 일반카메라를 사용하여 비행영상을 획득한다. 개발한 외장형 계측시스템은 환경시험과 지상시험, 그리고 전투기에 장착하여 비행시험을 수행함으로서 성능을 입증하였다.

• Asian Journal of Atmospheric Environment
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• 제4권2호
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• pp.89-96
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• 2010

To identify the domains that have the greatest impacts on air quality at the surface, both the upwind and downwind areas of Seoul were determined by season using refined wind fields. Four consecutive days were selected as the study period typical of each season. The mesoscale meteorology of the study period was reproduced by using the MM5 prognostic meteorological model (PSU/NCAR Mesoscale Model) with horizontally nested grids. The gridded meteorological field, which was used on the study area of $242\;km{\times}226\;km$ with grid spacing of 2 km, was generated by using the CALMET diagnostic meteorological model. Upwind and downwind areas of Seoul were determined by calculating 24-hour backward and forward air parcel trajectories, respectively, with u, v, and w velocity vectors. The results showed that the upwind and downwind areas were extended far to the northwest and the southeast as a result of high wind speeds in the spring and winter, while they were restricted on the fringe of Seoul in the summer and fall.

• Journal of Power Electronics
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• 제15권6호
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• pp.1547-1558
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• 2015

A predictive functional control (PFC) scheme for permanent magnet synchronous motor (PMSM) servo systems is proposed in this paper. The PFC-based method is first introduced in the control design of speed loop. Since the accuracy of the PFC model is influenced by external disturbances and speed detection quantization errors of the low distinguishability optical encoder in servo systems, it is noted that the standard PFC method does not achieve satisfactory results in the presence of strong disturbances. This paper adopted the Kalman filter to observe the load torque, the rotor position and the rotor angular velocity under the condition of a limited precision encoder. The observations are then fed back into PFC model to rebuild it when considering the influence of perturbation. Therefore, an improved PFC method, called the PFC+Kalman filter method, is presented, and a high performance PMSM servo system was achieved. The validity of the proposed controller was tested via experiments. Excellent results were obtained with respect to the speed trajectory tracking, stability, and disturbance rejection.

• 대한전기학회논문지
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• 제38권12호
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• pp.995-1006
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• 1989

로보트 매니퓰레이터가 컨베이어 상의 파트를 추적 하면서 작업을 수행하는 것은 작업 효율의 증가에 크게 기여한다. 본 논문은 컨베이어 상의 파트를 추적하기 위한 로보트 매니퓰레이터의 동작계획 알고리즘을 제안한다. 로보트 매니퓰레이터의 추적 동작은 밸트의 속도, 추적 시작 시간에서의 파트와 로보트 핸드의 위체이 의하여 결정된다. 이때 토크 및 관절 속도, 관절 가속도, 관절 저크의 제한범위가 모두 고려되며, 최소의 정착시간을 갖는 추적 궤적이 생성된다. 추적 해는 linearr quadratic tracking문제로 접근하여 구한다. 로보트매니퓰레이터의 동적 방정식은 파라메터의 함수 성능 지수를 최소화 하는 동적 방정식의 해는 동적 계획법에 의하여 구한다. ${\mu}-VAX_@$에 의한 시뮬레이션 결과를 제시한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.87-90
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• 2001

This paper presents a design of new type biped robot and dynamic walking simulation for this system. The robot is distinguished from other one by which has a parallel mechanism type trunk and lead-screw type actuators to drive the joints of the trunk, knee and ankle. The basic consideration on the design is that it is able to accommodate itself to human's daily environments without any other modification of around and also to operate its upper limbs more smoothly with a spine functional trunk. It is designed according to a human with about 130 cm height and about 30 kg weight. And it also is able to dynamically walk on an even ground. It has constructed with total 14 DOFs which have two legs, a hip, and a trunk. The joints of each leg and trunk are adopted with a parallel structure which has good kinematic characteristics and take light weight. To test of the capacity of joint actuators and to analysis of the dynamic properties of the biped robot, optimized trunk trajectory is determined by means of an approximated FFT method based on ZMP criteria, and dynamic simulation is performed using DADS with a 1.1 time/step velocity on the even ground during four steps.

• 한국지능시스템학회논문지
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• 제8권2호
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• pp.106-116
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• 1998

유연 로봇 매니퓰레이터의 위치 제어 알고리즘에 대한 연구를 하였다. 제안하는 알고리즘은 신경회로망의 학습 알고리즘에 근거한 자동 구축 퍼지 적응 제어기(ACFAC : Automaitc Constructed Fuzzy Adaptive controller)에 기본으로 한다. 제안하는 시스템은 비지도 경쟁 학습 알고리즘을 사용하여 입력 변수의 멤버십 함수와 지도 Outstar 학습 알고리즘을 사용하여 출력 정보를 학습시킨다. ACFAC는 유연 로봇 매니퓰레이터의 동력한 모델을 필요로 하지 않는다. ACFAC는 유연 로봇 매니퓰레이터의 끝점이 원하는 궤적을 따라가도록 설계되었다. 이 제어기의 입력은 위치 오차, 위치 오차의 미분 값과 오차의 variation에 의해 결정된다. ACFAC의 우수서을 보여주기 우해서 PID 제어나 신경회로망 알고리즘을 사용한 결과와 비교를 하였다.