• 제어로봇시스템학회논문지
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• 제3권1호
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• pp.61-66
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• 1997

로보트 매니퓰레이터가 일정한 접촉 힘을 유지하며 공작물의 표면을 따라가게 하는 작업은 많은 자동화 생산공정에서 유용하게 이용될 수 있다. 일반적인 위치제어용 산업용 로보트를 이러한 공정에 사용하기 위해서는 접촉힘이 계측되어 로보트의 제어에 이용되어야만 한다. 이 연구는 accommodation force control 방식으로 산업용 로보트를 제어하여 edge-following에 응용하도록하며, 접촉 힘의 계측에는 wrist force sensor를 사용한다. 이 시스템의 궤도추적속도와 force regulation 등이 예견제어에 의해 향상될 수 있다. 예견제어에 의해 설계된 전체 제어 시스템은 feedback 제어기와 feedforward 예견제어기로 구성된다. 여기서, 시스템의 안정성은 feedback 제어기에 의해서 결정되며, 예견제어기는 시스템에 미치는 외란을 통제하는 것을 주 기능으로 한다. 일반적으로 선형제어 방식을 채택한 경우와 예견제어를 이용한 edge-following을 실험을 통해 비교함으로써, 예견제어의 효용성을 확인한다.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.263-267
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• 2007

This study proposes a new methodology to estimate the traffic capacity of a personal rapid transit(PRT) system. The proposed method comprises three steps. The first step models the guideway network(GN) of PRT as a digraph, where its node and link represent a station and a one-way guideway link between two stations, respectively. Given local vehicle control strategies, the second step formulates the local traffic capacities through the nodes and links of the GN model. The third step estimates the worst-case local traffic demands based on a shortest-path routing algorithm and an empty vehicle allocation algorithm. By comparing the traffic estimates to the local traffic capacities, we can determine the feasibility of the given GN in traffic capacity.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.804-809
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• 2004

This paper introduces a link-type tracked vehicle which is developed for demining operations. The vehicle consists of three parts - front frame, rear frame and body. The front frame is connected to the rear frame by a rotational passive adaptation mechanism which is a driving mechanism of the vehicle. Additionally, the demining system which is adaptable to mobile robot is developed to clear small Anti-Personnel(AP) mines with inexplosive method. In other words, assembled rakes unearth mines by their opposite rotation to the direction of the robot. Finally, the motions of demining rakes and design parameters of the demining system are analyzed.

• 한국항공우주학회지
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• 제43권5호
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• pp.413-421
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• 2015

큐브위성은 2003년 처음 발사된 이후로 지금까지 230기 이상이 발사되었다. 작은 크기와 가벼운 무게로 인해 발사비용이 저렴한 큐브위성은 일반적인 발사체의 남는 공간을 이용하여 발사되고 있다. 그러나 이러한 발사 방법은 주 탑재위성의 준비일정에 따라 발사 일정이 유동적인 단점이 있다. 이에 새로운 대안으로 정기적이고 발사횟수가 많은 국제우주정거장 물자수송 발사체를 이용하여 큐브위성을 ISS로 운송한 뒤에 로봇팔을 이용하여 발사하는 방법이 제안되고 있다. 본 논문에서는 국제우주정거장에서 분리되는 방향과 각도에 따라 생성되는 큐브위성의 궤도를 분석하였다. 또한 분석되는 궤도에 따른 임무수명과 ISS와의 충돌 가능성을 분석하여 충돌 위험을 최소화하고 위성수명을 최대로 하는 최적의 로봇팔 각도를 계산하였다.

• 대한기계학회논문집
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• 제17권2호
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• pp.267-276
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• 1993

본 연구에서는 우선 네트워크의 기본 이론을 소개하고, 이를 바탕으로 로봇의 궤적계획에 이용하기 위한 변수, 구속조건, 에너지를 정의하며, 네트워크가 국부적 최 소 상태에 빠지는 것을 방지하기 위하여 Temperature Adding을 이용한 적절한 가중치 조절로 작업 공간상에 장애물이 정지하고 있는 경우와 장애물이 움직이는 경우, 같은 작업 공간상에서 동시에 움직이는 두 대의 로봇들의 충돌회피문제 등 여러 종류의 궤 적 계획 문제에 적용시켜 보고자 한다. 이와같이 궤적계획 문제를 신경회로를 이용 하여 다루게 되면, 신경회로망의 링크수나 장애물의 변화등 상황의 변화에 따르는 복 잡한 모델링 전개가 필요 없어지고, 여유 자유도를 가지는 경우에도 별도의 성능지수 를 위한 인위적인 조작을 요구하는 알고리즘의 개발이 필요없이 스스로가 최소의 에너 지 상태를 찾아가게 되며, 병렬실(parallel processing) 계산방식으로 각 링크의 위치 를 동시에 구할 수 있게 되어 실시간 제어의 가능성을 제시하여 준다.

• 로봇학회논문지
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• 제5권3호
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• pp.270-277
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• 2010

Various robot platforms have been designed and developed to perform given tasks in a hazardous environment for the purpose of surveillance, reconnaissance, search and rescue, and etc. We have considered a terrain adaptive hybrid robot platform which is equipped with rapid navigation on flat floors and good performance on overcoming stairs or obstacles. Since our special consideration is posed to its flexibility for real application, we devised a design of a transformable robot structure which consists of an ordinary wheeled structure to navigate fast on flat floor and a variable tracked structure to climb stairs effectively. Especially, track arms installed in front side, rear side, and mid side are used for navigation mode transition between flatland navigation and stairs climbing. The mode transition is determined and implemented by adaptive driving mode control of mobile robot. The wheel and track hybrid mobile platform apparatus applied off-road driving mechanism for various professional service robots is verified through experiments for navigation performance in real and test-bed environment.

• 로봇학회논문지
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• 제19권2호
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• pp.149-158
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• 2024

This paper presents a robust autonomous navigation and reconnaissance system for tracked robots, designed to handle complex multi-floor indoor environments with stairs. We introduce a localization algorithm that adjusts scan matching parameters to robustly estimate positions and create maps in environments with scarce features, such as narrow rooms and staircases. Our system also features a path planning algorithm that calculates distance costs from surrounding obstacles, integrated with a specialized PID controller tuned to the robot's differential kinematics for collision-free navigation in confined spaces. The perception module leverages multi-image fusion and camera-LiDAR fusion to accurately detect and map the 3D positions of objects around the robot in real time. Through practical tests in real settings, we have verified that our system performs reliably. Based on this reliability, we expect that our research team's autonomous reconnaissance system will be practically utilized in actual disaster situations and environments that are difficult for humans to access, thereby making a significant contribution.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.867-872
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• 2007

A tracked robot has an excellent mobility on the rough terrain. Especially, a tracked robot for driving has to get structural function in the every field. In this paper, we propose a tracked robot of a small rear wheel typed. Also compared and estimated a driving analysis about the tracked robot in considered the general environment. Compared 2 models are different in size of rear wheels but front wheels are same size each other. From comparing model, the radius of front wheels is 100mm and the radius of rear wheels is 100mm. The radius of front wheels is 100mm and the radius of rear wheels is 70mm from proposed tracked robot. Depend on these radiuses of values we are known driving torque values of an actuating wheel using Recurdyn. And estimated stress of rotated track by an actuating wheel using Ansys. finally, the designed robot has size of $600mm\;{\times}\;330mm\;{\times}\;150mm$, weight is 27kg and the tracked robot is actuated by 2 geared DC motors.

• 한국정밀공학회지
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• 제15권1호
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• pp.78-86
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• 1998

This paper presents a numerical method of the minimum-time trajectory planning for a robot manipulator amid obstacles. Each joint displacement is represented by the linear combination of the finite-term quintic B-splines which are the known functions of the path parameter. The time is represented by the linear function of the same path parameter. Since the geometric path is not fixed and the time is linear to the path parameter, the coefficients of the splines and the time-scale factor span a finite-dimensional vector space, a point in which uniquely represents the manipulator motion. The displacement, the velocity and the acceleration conditions at the starting and the goal positions are transformed into the linear equality constraints on the coefficients of the splines, which reduce the dimension of the vector space. The optimization is performed in the reduced vector space using nonlinear programming. The total moving time is the main performance index which should be minimized. The constraints on the actuator forces and that of the obstacle-avoidance, together with sufficiently large weighting coefficients, are included in the augmented performance index. In the numerical implementation, the minimum-time motion is obtained for a planar 3-1ink manipulator amid several rectangular obstacles without simplifying any dynamic or geometric models.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1199-1205
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• 1993

It has been well known that the assumption of full state availability is one of the most important restrictions to the practical realization of VSCS. And several attempts to alleviate the assumption had been made. However, it is not easy to find a positive scheme among them. Recently, an output feedback variable structure control system(OFVSCS) was proposed and the effectiveness of the scheme was validated for the disturbance free systems. The purpose of this study is to propose a robust OFVSCS that have the robust properties against process parameter variations and external distrubances by extending the basic OFVSCS and to evaluate its control performances through power system stabilizer design example. The ROFVSCS is composed of dynamic switching function and output feedback switching control inputs that are constructed by the use of the unknown vector modeling technique. With the proposed scheme, existence of sliding mode is guaranteed and any nonzero bias can be suppressed in the face of disturbances and process parameter variations as far as well-known matching condition is satisfied. Due to the fact that the ROFVSCS is driven by small number of measured informations, the practical application of VSCS for the systems with unmeasurable states and for high order systems that conventional schemes cannot be applied, is possible with the proposed scheme. It is noticeable that the implementation cost of VSCS can be considerably reduced without sacrifice of control performances by adopting ROFVSCS since there is no need measure the states with high measurement cost.