• Journal of the Korean Institute of Intelligent Systems
• /
• v.13 no.2
• /
• pp.137-147
• /
• 2003

The fuzzy control and implementation of a new three-dimensional(3-D) inverted pendulum system are addressed. In comparison with conventional 1-D and 2-D systems, the 3-D inverted pendulum system is a proper benchmark system to simulate human's control action which includes the up and down motion to stabilize an inverted pendulum. To investigate the characteristics of the 3-D inverted pendulum system and to design of a fuzzy controller, we derive dynamic equations of the mechanism including a 3-axis cartesian robot and an inverted pendulum. We propose a design method of a fuzzy controller of the yaw and pitch angles of an inverted pendulum. In the design, the redundant degree-of-freedom(DOF) of the robot and the constrained workspace are taken into account. The performance of the proposed system is proved by experimental results using a developed PC-based Multi-Motion Control(MMC) board.

• Proceedings of the KIEE Conference
• /
• 2004.07d
• /
• pp.2278-2280
• /
• 2004

이 논문은 이동식 수레형 도립진자 제어에 있어서 비선형적인 특성을 발생시키는 원인중의 하나인 마찰력을 보상하는 방법에 대하여 고찰한다. 여기에 사용된 방법은 모터에 전압을 인가하였을 때의 이동식 수레형 도립진자의 위치와 속도에 대한 데이터를 가지고, 가우시안 반복을 적용한 비선형 최소 자승법을 이용하여 마찰력을 추정하고, 모델링을 하여, 모델링 된 파라미터를 이용하여 비선형적인 특성을 최소화하는 것이다. 이 논문의 주된 결과는 수학적으로 모델링 한 마찰력이 실제의 마찰력과 유사하며, 이 마찰력을 보상함으로서, 이동식 수레형 도립진자의 제어 성능이 향상되었음을 보여준다. 따라서 이 결과는 기존의 마찰력을 무시하고, 이동식 수레형 도립진자를 제어하였을 때보다 마찰력을 보상하였을 때가 더욱 안정된 시스템이 됨을 실험적으로 확인한다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1995.10b
• /
• pp.174-179
• /
• 1995

본 논문데서는 부하외란이나 시스템 내부 파라미터의 변동시에 적응력이 저하되는 종래의 PI제어기와, 정상상태 잔류편차가 존재하는 퍼지 제어기의 단점을 극복하기 위한 적 응 퍼지 제어 기법을 제안하였고, 이를 도립 진자 시스템에 적용하였다. 운송차의 위치 및 진자 각도의 오차, 오차의 변화량에 따라 퍼지 추론을 행하여 PI 제어기의 가중치를 결정하 는 구조로, P제어기는 운송차 및 진자의 오차가 과도 상태에서의 영역에서 사용되어 속응성 과 고정도의 특성을 얻는다. 1제어기는 정상상태에서의 정도 향상에 이용되었다. 특히, 제안 하는 적응 퍼지 제어기는 운송차의 위치 오차에 대한 PI 동작과, 진자의 각도 오차에 대한 PI 동작을 각각 퍼지 추론에 의해 부드럽게 전환함으로서 고유 불안정의 시스템인 도립 진 자 시스템의 안정화 제어에 적용하였다.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1811-1812
• /
• 2007

본 논문에서는 Fuzzy-PID Control을 이용한 2축 도립진자를 제어한다. X-Y 축을 움직이는 카트에는 도립진자가 세워져 있으며 카트가 2축의 평면상에 원하는 위치로 빠르고 정확하게 이동할 수 있게 하는 동시에 도립진자의 균형을 깨뜨리지 않고 움직이는 것을 제어의 목표로 한다. Fuzzy-PID Control은 도립진자의 균형에 대한 제어뿐만 아니라 로봇의 위치 제어까지 적용된다. 본 연구 논문에서는 이러한 Fuzzy-PID 적용 시스템에 대한 시뮬레이션을 실행함으로 그 우수성을 입증 하고자 한다.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.30 no.4
• /
• pp.180-190
• /
• 2018

The preliminary study was carried out to utilize the rolling porous pendulum plate as a hybrid system combining blocking and extracting of wave energy. The Galerkin method suggested by Porter and Evans (1995) was used to solve the diffraction and radiation problems to obtain reflection and transmission coefficient, roll displacement, extracted power. The Galerkin method provides better convergence than the matched eigenfunction expansion method (MEEM), which improves the accuracy of the analytical solution even if the CPU time is shorter. The porous plate can not be said to be more effective than the impermeable plate in terms of wave energy extraction and wave blocking, but it has the advantage of reducing the wave load and exchanging seawater.

• Knowledge Management Research
• /
• v.22 no.2
• /
• pp.227-246
• /
• 2021

In the context of the global pandemic caused by COVID-19, emergency alert text messages can violate the privacy of confirmed corona positive cases. This study used conjoint analysis to identify the essential information factors and the privacy invasion information factors of local government initiated safety notices. As a result of this study, we found eight essential information factors, including all routes of the confirmed case and ten privacy invasion factors of safety notices. In addition, we found that there is a similarity between the combinations of information perceived to be the most essential and perceived as the most significant privacy invasion; both combinations include the confirmed case's personal and route information. This study ultimately tried to suggest a way to lower the concern about privacy invasion of the confirmed cases without damaging the emergency alert text messages' essential information. We expect that this study will provide researchers and policymakers interested in disaster communication with valuable theoretical and practical implications.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.16 no.2
• /
• pp.162-172
• /
• 2011

This paper proposes embedded System of two wheeled inverted pendulum robot designed by model based design method, using MATLAB/SIMULINK and LEGO NXT Mindstorms. At first, stability and performance of controller is verified through modeling and simulation. After that direct conversion from simulation model to C code is carried and effectiveness of controller is experimentally verified. Two wheeled inverted pendulum robot has basic function about autonomous balancing control using principle of inverted pedulum and it is also possible to arrive at destination. In this paper, state feedback controller designed by quadratic optimal control method is used. And quadratic optimal control uses state feedback control gain K to minimize performance index function J. Because it is easy to find gain, this control method can be used in the controller of two wheeled inverted pendulum robot. This proposed robot system is experimentally verified with following performances - balancing control, disturbance rejection, remote control, line following and obstacle avoidance.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.12 no.4
• /
• pp.55-61
• /
• 2008

One of the most recent base-isolation systems to improve the earthquake resistance of structures is the Friction Pendulum System(FPS). Simple in design but with versatile properties, the FPS has been used in some of the world s largest seismically isolated buildings, bridges and chemical tanks. FPS using PTFE(Polytetrafl-uoroethylene) based material has been developed to provide a simple and effective way for structures to achieve earthquake resistance. PTFE materials are soft, and are apt to become deformed easily after a few working cycles. In this study, magnetic force is used rather than the usual PTFE materials to improve the material shortcomings. A MF-FPS(Magnetic force-Friction Pendulum System) is proposed, and us shown to effectively protect structures against earthquakes. To demonstrate the advantages of this new system, the MF-FPS is compared with FPS as an attempt to prove its performance. A six-degree-of-freedom model is considered as a numerical example. The ground acceleration data of El Centro, Mexico and Gebze earthquakes are used as seismic excitations. The results showed that MF-FPS improved performance compared with FPS.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.26 no.1
• /
• pp.16-22
• /
• 2016

The research on two-wheeled inverted pendulum (TWIP) mobile robots has been ongoing in a number of robotic laboratories around the world. In this paper, we consider a robust controller design for the TWIP mobile robot driving on uniform slopes. We use a 2 degree-of-freedom (DOF) model which is obtained by restricting the spinning motion in a 3 DOF motion dynamic equation. In order to design the robust controller guaranteeing stability of the TWIP mobile robot driving on inclined surface, we propose a sliding mode control based on the theory of variable structure systems and design a sliding surface using the theory of the linear quadratic regulation (LQR). For simulation, the dynamic model of the TWIP mobile robot is constructed using Mathworks' Simulink and the sliding mode control is also implemented using Simulink. From simulation results, we show that the proposed controller effectively controls the TWIP mobile robot driving on slopes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.697-700
• /
• 2022

Recently, as of March 18, 2022, Corona-19 (COVID-19) has 8,250,000 confirmed persons and 11,481 deaths, and has been increasing since the outbreak in 2020. By limiting the number of people and time, we are showing how our daily life changes depending on the number of confirmed coronas. Therefore, in this study, we implemented an algorithm that predicts the number of confirmed people the next day to help minimize damage to the limits of daily life. This algorithm is an algorithm that predicts the number of confirmed persons on the next day using the number of confirmed persons for 3 days. It is predicted by adding the RNN and Dense layers using the Sequential model, and the number of people is subdivided by region. In order to predict the limit, we matched the personnel limit based on the number of fixed persons per day based on Seoul.