• 제어로봇시스템학회논문지
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• 제15권12호
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• pp.1223-1231
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• 2009

We derive a systematic and iterative calibration algorithm, and position and pose estimation algorithm for the mobile robots in formation system based on the vision system. In addition, we develop a coordinate matching algorithm which calculates matched sequence of order in both extracted image coordinates and object coordinates for non interactive calibration and pose estimation. Based on the results of calibration, we also develop a camera simulator to confirm the results of calibration and compare the results of simulations with those of experiments in position and pose estimation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.153-156
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• 2002

The remotely operated underwater robotic vehicle system has been required to inspect some objects such as baffle former bolts and remove foreign objects in reactor vessel of nuclear power plant. In this paper, we have designed the remotely operated underwater robotic vehicle system that includes a long reach arm that is composed of 4 joints to remove foreign objects in a narrow space, a camera for visual test, instrument sensors for vehicle positioning, 4 thrusters for underwater navigation of vehicle, and supervisory control system implemented with industrial PC that includes robot simulator that has the functions of real time visualization, robot work planning and etc.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.751-758
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• 2016

The modifiable walking pattern generation (MWPG) algorithm can handle dynamic walking commands by changing the walking period, step length, and direction independently. When an infeasible command is given, the algorithm changes the command to a feasible one. After the feasibility of the navigational command is checked, it is translated into the desired center of mass (CM) state. To achieve the desired CM state, a reference CM trajectory is generated using predefined zero moment point (ZMP) functions. Based on the proposed algorithm, various complex walking patterns were generated, including backward and sideways walking. The effectiveness of the patterns was verified in dynamic simulations using the Webots simulator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.549-551
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• 1998

This paper deals with the new gait implementation of biped walking robot(IWR-III). In the case of using old gait. The trunk should be stopped during the phase changing time. But using new gait, the trunk moves continuously for all walking time. As a result, IWR-III has a walking gait similar to human being, and the motion of balancing joints can be reduced by the trunk ahead effect in the double support phase, moreover, ZMP tracking is improved, therefore the stability of IWR-III is improved. The trajectory is planned with a 5th order spline interpolation and stability of IWR-III is certified with a biped simulator.

• 항공우주시스템공학회지
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• 제15권4호
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• pp.75-84
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• 2021

A novel robot-operating-system-based flight and mission state communication node for X-Plane 11 flight control simulation environments and its simulation results were discussed. Although the proposed communication method requires considerable implementation steps compared with the conventional MATLAB/Simulink-based User Datagram Protocol (UDP) block utilization method, the proposed method enables a direct comparison of cockpit-view images captured during flight with the flight data. This comparison is useful for data acquisition under virtual environments and for the development of flight control systems. The fixed/rotary-wing and ground terrain elements simulated in virtual environments exhibited excellent visualization outputs, which can overcome time and space constraints on flight experiments and validation of missionary algorithms with complex logic.

• 제어로봇시스템학회논문지
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• 제15권10호
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• pp.1029-1038
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• 2009

This paper proposes a gain switching algorithm for joint position control of a hydraulic humanoid robot. Accurate position control of the lower body is one of the basic requirements for robust balance and walking control. Joint position control is more difficult for hydraulic robots than it is for electric robots because of an absence of reduction gear and better back-drivability of hydraulic joints. Backdrivability causes external forces and torques to have a large effect on the position of the joints. External ground reaction forces therefore prevent a simple proportional-derivative (PD) controller from realizing accurate and fast joint position control. We propose a state feedback controller for joint position control of the lower body, define three modes of state feedback gains, and switch the gains according to the Zero Moment Point (ZMP) and linear interpolation. Dynamic equations of hydraulic actuators were experimentally derived and applied to a robot simulator. Finally, the performance of the algorithm is evaluated with dynamic simulations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1825-1826
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• 2008

본 논문은 3D 기반 시뮬레이터를 이용한 새로운 휴머노이드 로봇 개발 플랫폼 설계에 관한 연구이다. 높은 자유도의 휴머노이드 로봇의 빠르고 쉬운 개발을 위해서는 편리하며 개발에 효율적인 시뮬레이터 개발 플랫폼이 필수적이다. 실제 로봇 제어를 고려한 새로운 3D 기반의 시뮬레이터 설계 및 구조를 제시한다. 또한, 휴머노이드 로봇의 주어진 임무 수행시 실제 로봇의 움직임에 따른 대상 물체의 탐지 및 실시간 시뮬레이터에의 적용에 의한 로봇 동작 제어 방법을 제시한다. 본 연구의 시뮬레이터의 효율성 및 정확성은 시뮬레이션 및 실제 로봇을 이용한 실험을 통하여 확인한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2877-2879
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• 2000

본 연구에서는 로봇의 3가지 기본모델에대해 OpenGL을 이용하여 3-D 로봇시뮬레이터를 구현하였다 또한. 개발된 로봇시뮬레이터에 간단한 출력제어기를 적용하여 제어알고리즘의 특성이 잘 나타나는지를 확인하였고, 실제 로봇의 하드웨어적 특성을 적용하여 로봇시뮬레이터와 실제로봇에서의 실험결과를 비교하였다.

• 한국태양에너지학회 논문집
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• 제34권4호
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• pp.123-129
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• 2014

Photovoltaic and fuel cell systems can be used as power source in mobile robots. At this time the photovoltaic system generally generate power in daytime. The starting time of fuel cell is slower than the lithium battery. To compensate for these disadvantages, a battery charge-discharge system is used. Especially the bi-directional converter is used mainly in the charge-discharge method. The controller in a buck converter controls the input voltage of the converter to meet the maximum power point tracking(MPPT) performance. First of all, the simulations of hybrid system for battery charge-discharge system in each step simulated using solar and fuel cell modeling as input source in PSIM. Experiment of the buck and bi-directional converter system is conducted through using photovoltaic/fuel cel simulator(pCube) instead of solar and fuel cell. This hybrid system for battery charge discharge using photovoltaic/fuel cell generates emergency power for the communication system in mobile robot.

• 전기학회논문지
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• 제58권8호
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• pp.1605-1614
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• 2009

The technique of simultaneous localization and mapping is the most important research topic in mobile robotics. In the process of building a map in its available memory, the robot memorizes environmental information on the plane of grid or topology. Several approaches about this technique have been presented so far, but most of them use mapping technique as either grid-based map or topology-based map. In this paper we propose a frame of solving the SLAM problem of linking map covering, map building, localizing, path finding and obstacle avoiding in an automatic way. Some algorithms integrating grid and topology map are considered and this make the SLAM performance faster and more stable. The proposed scheme uses an occupancy grid map in representing the environment and then formulate topological information in path finding by A${\ast}$ algorithm. The mapping process is shown and the shortest path is decided on grid based map. Then topological information such as direction, distance is calculated on simulator program then transmitted to robot hardware devices. The localization process and the dynamic obstacle avoidance can be accomplished by topological information on grid map. While mapping and moving, pose of the robot is adjusted for correct localization by implementing additional pixel based image layer and tracking some features. A laser range finer and electronic compass systems are implemented on the mobile robot and DC geared motor wheels are individually controlled by the adaptive PD control method. Simulations and experimental results show its performance and efficiency of the proposed scheme are increased.