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Fast Terminal Sliding Control Application for Second-order Underactuated Systems
Ansu Man Singh,하쾅 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.8
In this paper, we propose a robust and finite-time control method, based on the terminal sliding mode (TSM), for a class of two-degree-of-freedom (2-DOF) underactuated electromechanical systems subject to bounded uncertainties and disturbances. First, the proposed Fast Terminal Sliding Mode (FTSM) method is presented. Then for the underactuated system control, hierarchical sliding surfaces are defined, consisting of two layers. In the first layer, separate FTSM sliding functions are selected for each state of the system. In the second layer, the system sliding manifold is a linear combination of the first layer sliding surfaces. A control law is derived and stability conditions of the nonlinear system are obtained by using the Lyapunov theory. To verify the effectiveness of our proposed method, the developed control technique is applied to control both the swinging load and the cart position of an underactuated gantry crane. Extensive simulation and real-time experiments demonstrate enhanced performance of the system and robustness against parametric variations in comparison to conventional TSM and sliding mode control.
Roy, Ansu K.,Ahmad, Z.,Prasad, A.,Prasad, K. Techno-Press 2012 Advances in materials research Vol.1 No.4
The present study addresses the problem of quantitative prediction of effective complex relative permittivity of Barium Titanate/Polyvenylidene Fluoride (PVDF) and $(Bi_{0.5}Na_{0.5})_{0.94}Ba_{0.06}TiO_3$/Poly(VDF-TrFE) biphasic ceramic-polymer composites. Theoretical results for effective relative permittivity derived from several dielectric mixture equations were fitted to the experimental data taken from the works of Prasad et al. (2010), Wang et al. (2004), Takenaka et al. (1991) and Yamada et al. (1982). The study revealed that out of the different test equations, only a few equations like modified Rother-Lichtenecker equation, Dias-Dasgupta equation or Rao equation for the real part and Bruggeman equation for the imaginary part of complex permittivity well fitted the corresponding experimental results. In the present study, some of the equations were used in their original forms, while some others were modified by choosing suitable shape-dependent parameters in order to get reasonably good agreement with experimental results. Besides, the experimental results have been proposed in the form of a mathematical model using first order exponential growth, which provided excellent fits.
Successive Loop Closure Based Controller Design for an Autonomous Quadrotor Vehicle
Singh, Ansu Man,Lee, Deok Jin,Hong, Dong Pyo,Chong, Kil To Trans Tech Publications, Ltd. 2013 Applied Mechanics and Materials Vol. No.
<P>In this paper, a new systematic approach for designing a self-tuning controller for an autonomous quadrotor robot is introduced.In order to design the self-tuning controller, first, a linearized dynamic model of a quadrotor about hovering positions is derived, and thenthe successive loop closure approach is applied to design the self-tuning PID controller of the attitude, altitude and velocity for the autonomous flying capability of the flying robot. In addition, nonlinearities of the design model are also imposed in the control loop by takinginto account the saturation of actuators. For the verification of the effectiveness of the proposed controller, various simulation studiesare carried out in terms of the accuracy and robustness.</P>
대형기관 모사 정적연소실에서 매립지 가스의 연소특성에 대한 연구 (Ⅳ)
고안수(Ansu Ko),엄인용(Inyong Ohm),권순태(Soon Tae Kwon) 대한기계학회 2015 大韓機械學會論文集B Vol.39 No.2
본 논문은 대형 상용기관을 모사한 정적연소실에서 매립지 가스의 연소 특성에 대한 복수의 논문 중 네 번째로, 열 발생 특성과 가시화 결과를 관찰하여 토치 연소의 특징을 논의하였다. 분석 결과 토치 연소는 주 연소실에 형성된 화염 면을 토치에서 분출되는 가스가 가속시킴으로 연소를 촉진한다. 이 때 오리피스 직경이 4mm일 때는 토치에서 고온의 가스가 분출되며, 6mm 이상에서는 토치에서 형성된 화염이 직접 오리피스를 통과한다. 또한 메탄 분율, 토치 체적 그리고 오리피스 크기가 상호 연관적으로 작용하여 다양한 연소 형태를 야기하고 이에 따라 토치 연소의 효과가 매우 다르게 나타난다. 마지막으로 실물기관에서 연소 과정의 일관성을 보장하는 적절한 토치의 조건은 6mm 이상의 오리피스 직경과 0.15 이하의 오리피스 면적비를 동시에 만족시키는 것이다. This paper is the fourth on the combustion characteristics of the landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine and the second dealing with torch ignition. It discusses the combustion characteristics of torch ignition on the basis of the heat release and visualization. The results show that the jet and/or spout from the torch promote combustion by accelerating the flame front in the main combustion chamber. In addition, a hot gas jet exists when the orifice diameter is 4 mm, whereas the flame passes directly through the orifice if the diameter is 6 mm or greater. In addition, the effect of torch ignition differs according to the combination of the methane fraction, torch volume, and orifice size because various combustion processes occur as a result of the interaction of these parameters. Finally, it was found that the most suitable torch should have an orifice diameter of not less than 6 mm and an area ratio of not more than 0.15 to secure a consistent combustion process in a real engine.
중등예비 체육교사들의 교육 봉사활동 경험에 대한 인식과 반응
이안수,배종희,노현호 이화여자대학교 교과교육연구소 2015 교과교육학연구 Vol.19 No.1
This study aims to investigate secondary physical education teacher candidates’ perceptions and reactions on the experiences of the educational service activity program. For this purpose, five male and two female teacher candidates were selected from K college of education of D region. The data were collected through participant observation, semi-structured interview, journal and documentation and analyzed using an inductive analysis. The authenticity of the data was verified by member check, peer debriefing, and triangulation. The findings indicated that physical education candidates perceived the experiences of educational service activities as an easy-to-start activity, perceived themselves as observers from outside the school, and considered these experiences as good opportunities to get matured as pre-service teachers. As reactions to educational service activities, they showed an attitude to study the curriculum of the service program more sincerely and they hoped that the educational service activities were more closely linked to their major. Based on these findings, teacher education needs to develop service learning course and collaborates with their community. 본 연구는 중등예비체육교사들이 교육봉사활동과목을 이수하는 과정에서 봉사학습 경험에 대한 인식과 반응을 알아봄으로써 봉사학습 프로그램의 문제점과 그 원인을 알아보고 개선방향을 검토하여 봉사학습 프로그램 개발을 위한 정보를 제공하는데 그 목적이 있다. 이러한 연구 목적을 달성하기 위하여 D지역 K사범대학 교육봉사활동에 참여한 중등예비체육교사 중 남학생 5명, 여학생 2명, 총 7명을 연구 참여자로 선정하였으며, 참여관찰, 심층면담, 문서 분석의 방법으로 자료를 수집하였다. 수집된 자료들은 귀납적인 과정으로 분석되었으며, 집중관찰, 연구 참여자 확인,동료간 협의, 전문가 협의 등을 통해 자료의 진실성을 확보하였다. 교육봉사활동에 대한 인식으로 첫째, 누구나 쉽게 시작할 수 있는 활동으로 인식하였으며, 둘째, 학생들 자신을 교육현장을 맴도는 참관자로 생각하였다. 셋째, 교육봉사활동을 중등예비체육교사로서 내·외적으로 성장할 수 있는 기회로 인식하였다. 활동 후 반응으로는 교육봉사활동에 대하여 스스로의 교사상을 정립하고 앞으로 학습연구에 더 정진하려는 태도를 가졌으며, 활동이 좀 더 전공과 직접적으로 관련된 것으로 이루어지기를 희망하였다. 이와 같은 이유로 좀 더 교육적인 봉사학습 프로그램 개발을 위하여 관련 전공 기초자료를 작성하고, 주변의 학교들과 협력관계를 맺어 구체적인 활동계획을 세워야할 것이다.