Nonlinear Model Predictive Control for Multiple UAVs Formation Using Passive Sensing

신효상,탁민제,김현진 한국항공우주학회 2011 International Journal of Aeronautical and Space Sc Vol.12 No.1

In this paper, nonlinear model predictive control (NMPC) is addressed to develop formation guidance for multiple unmanned aerial vehicles. An NMPC algorithm predicts the behavior of a system over a receding time horizon, and the NMPC generates the optimal control commands for the horizon. The first input command is, then, applied to the system and this procedure repeats at each time step. The input constraint and state constraint for formation flight and inter-collision avoidance are considered in the proposed NMPC framework. The performance of NMPC for formation guidance critically degrades when there exists a communication failure. In order to address this problem, the modified optimal guidance law using only lineof-sight, relative distance, and own motion information is presented. If this information can be measured or estimated, the proposed formation guidance is sustainable with the communication failure. The performance of this approach is validated by numerical simulations.

공진화 기법을 적용한 틸트 로터 항공기의 제어기 최적화에 관한 연구

신효상,민병문,탁민제 한국항공우주학회 2005 한국항공우주학회 학술발표회 논문집 Vol.- No.-

국가관세종합정보망 전면재구축 사업을 통한 EA 성과연구

박성식,신효상,이석준 한국엔터프라이즈아키텍처학회 2013 정보기술아키텍처연구 Vol.10 No.4

Today, a corporate and the government is making significant investments in informatization in order to enhance competitiveness however, question on the outcome of information-oriented investment has continuously been posed and in order to resolve such problems, the technique of Enterprise Architecture (EA) Despite such fact, in the case of the central administrative institute, even if the EA maturity standard has continuously improved through continuous investment when compared to the past without deviation between institutes, the establishment of EA and the work utilization of EA compared to the management competence still is analyzed to be relatively weak. This study completed the preliminary feasibility study in 2012 for Korea Customs Service which has been appointed as the representative institute that best utilizes EA in the field of information operation and evaluation field in the 2010 EA Maturity Evaluation and it can become a case study that can contribute to more continuous development and improvement of other public institute EA by introducing the performance of EA-based 4th Korean National Customs Information Network which has entered into total reconstruction in 2013 and by identifying the implications of EA performance arising from such. 오늘날 기업과 정부는 조직 경쟁력 향상을 위해 정보화에 막대한 투자를 하고 있으나 정보화투자 성과에 대한 의문이 지속적으로 제기되어 왔고, 이러한 문제해결을 위해 EA 등의 기법이 제기되었다. 우리나라 정부는 2005년 정보자원을 관리하기 위한 방법으로 EA를 도입하기 시작하였다. 그러나 중앙행정기관의 경우 지속적 투자를 통해 EA성숙 수준이 향상되고 있음에도 여전히 EA 수립 및 관리 역량 대비 EA의 업무 활용은 상대적으로 취약한 것으로 분석되었다. 본 연구에서는 2010년 EA성숙도 평가에서 EA를 가장 잘 활용하는 대표적인 기관으로 선정된 관세청을 대상으로 2012년에 예비타당성 조사를 마치고, 2013년에 전면 재구축에 들어간 EA기반 제4세대 국가관세종합정보망의 성과를 소개하고, 이로 인한 EA 성과의 시사점을 도출함으로써 기타 공공기관 EA의 보다 지속적 발전과 개선에 기여할 수 있는 사례연구를 제시하고자 한다.

Dubins 집합을 이용한 다수 무인기의 임무 할당 및 경로 계획 통합 연구

오현동,신효상,탁민제 한국항공우주학회 2009 한국항공우주학회 학술발표회 논문집 Vol.2009 No.11

SEAD 임무를 위한 무인기의 분산협업제어 알고리즘 연구

이창훈,신효상,탁민제 한국항공우주학회 2011 한국항공우주학회 학술발표회 논문집 Vol.2011 No.11

본 논문은 무인기의 SEAD 임무를 위한 분산협업제어 알고리즘을 다룬다. SEAD 임무는 다수의 무인기를 다수의 목표물에 할당 시키는 임무 할당 문제로 정의 할 수 있다. SEAD 임무를 수행하는 전장 환경은 동적이며 불확실하고, 각 무인기는 전장 환경에 대해 부분적인 정보만을 획득 할 수 있다. 따라서 통합된 전장 상황 인식 정보를 기반으로 하는 중앙집중형 임무 할당 기법을 SEAD 임무에 적용하는 것은 문제가 된다. 본 논문에서는 각 무인기의 통신을 통한 정보 공유를 기반으로 하는 분산형 임무 할당 기법을 SEAD 임무에 적용한다. 내재협업과 RDTA 알고리즘을 고려하며, 수치 시뮬레이션을 수행하여 각 방법의 성능과 적용가능성에 대해 검토한다. This paper deals with distributed cooperative control algorithms for the SEAD(Suppression of Enemy Air Defense) of UAV. The SEAD mission is defined to be a task assignment problem of multiple UAVs performing multiple targets. The battle field of the SEAD mission is generally uncertain and dynamic. In addition, each UAV can only obtain a partially information of the battle field. Hence, it can be a problem to apply the centralized task assignment algorithm to the SEAD mission because most centralized task assignment algorithms generally use the integrated situational awareness. Accordingly, in this paper, we study the decentralized task assignment algorithms based on the information consensus through the communication channel of each UAV. The implicit coordination and RDTA(Robust Decentralized Task Assignment) algorithms are considered. We perform numerical simulations to analyze the performance and the applicability of both algorithms.

Efficient Aimpoint Tracking using Target Range Profiles of a Wideband FMCW Seeker

나원상,황익호,신효상,Antonios Tsourdos 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.4

This paper proposes an efficient aimpoint tracking filter for high-range resolution FMCW radar seekers. A modified probabilistic data association scheme is devised to deal with closely located measurements generatedby scatterers of an extended target and multipath clutter. In order to discriminate the aimpoint measurement fromothers, an approximate target range profile is used for calculating likelihoods of the validated measurements. Simulationresults show the effectiveness and the superior performance of the proposed approach.

우주비행체의 랑데부 및 도킹을 위한 적응 제어기법

윤형주(Hyungjoo Yoon),신효상(Hyo-Sang Shin),탁민제(Min-Jea Tahk) 한국항공우주학회 2008 韓國航空宇宙學會誌 Vol.36 No.11

본 논문에서는 일반적인 타원 궤도상에서의 두 위성체간의 랑데부와 도킹을 수행하기 위한 적응 제어기법을 개발하였다. 직교좌표계를 이용해서 나타낸 두 비행체간의 상대운동방정식을 일반적인 해밀토니안 운동방정식의 형태로 변환한 후, 불확실한 시스템 파라미터를 가진 동적시스템을 위해 개발된 적응제어기법을 적용하여 제어 알고리즘을 유도하였다. 시스템 파라미터를 추정하는데 투사기법을 적용하여 파라미터 추정값의 변화에 의한 특이점을 회피할 수 있도록 하였으며, 수치해석을 통하여 추적비행체의 질량이 불확실한 경우에 대하여 제어 알고리즘의 성능을 검증하였다. An adaptive control algorithm for spacecraft rendezvous and docking in a Keplerian orbit is presented. The equations of relative motion of two spacecrafts expressed in a local-vertical-local-horizontal rectangular frame are converted to a general Hamiltonian form, then an adaptive control method developed for the uncertain Hamiltonian system is applied to the rendezvous and docking problem. A smooth projection algorithm is applied to keep the parameter estimates inside a singularity-free region, and a numerical example shows that the developed controller successfully deals with the unknown mass of the chaser spacecraft.

부인과 수술 후 Ondansetron 과 병용한 Dexamethasone 의 오심 , 구토 예방과 제통 효과의 비교

이기흥(Kee Heung Lee),신효상(Hyo Sang Shin),전영훈(Young Hoon Jeon),김시오(Si Oh Kim),홍정길(Jung Gil Hong) 대한통증학회 2001 The Korean Journal of Pain Vol.14 No.1

N/A Background: Postoperative nausea and vomiting (PONV) are common after general anesthesia and patient controlled analgesia (PCA) using opioids. This study was designed to compare the effectiveness of ondansetron plus dexamethasone versus ondansetron alone in the prevention of PONV in a patient undergoing a PCA. Methods: We studied 166 ASA I, and II in-patients undergoing general anaesthesia for major gynecological surgery. After induction of anesthesia, Group 1 (n 64) received intravenous (IV) dexamethasone 10 mg and Group 2 (n 102) received IV saline 2 ml before the surgical incision. Each patient received IV meperidine 50 mg as a loading dose. Meperidine 5 mg/kg, ketorolac 3.6 mg/kg and ondansetron 8 mg diluted in 40 ml solutions were connected to PCA pump for postoperative pain control. Mean arterial blood pressure, heart rate, pain score and symptom-therapy score were checked at 1, 4, 8, 16, 24, and 36 hours after the PCA connection. Results: For Group 1 and Group 2, respectively, the overall incidence of PONV was 12.5% and 23.5%. The pain scores were lower in patients receiving a combination of ondansetron and dexamethasone than those on ondansetron alone at 4 hr (P < 0.05), 8 hr (P < 0.05) and 16 hr (P < 0.05). Conclusions: This study suggests that the combination of ondansetron and dexamethasone is not more effective than ondansetron alone in the prevention of postoperative nausea and vomiting in women having PCA following major gynecological surgery but is more effective for pain control.

흰쥐 중뇌동맥의 가역적 폐쇄시 뇌파 스펙트럼의 변화

박성식,백운이,임정옥,신효상 대한마취과학회 2001 Korean Journal of Anesthesiology Vol.41 No.1

표적 정보량을 최대화하는 피동 호밍궤적에 관한 고찰

나원상(Won-Sang Ra),신효상(Hyo-Sang Shin),정보영(Bo-Young Jung),황익호(Ick-Ho Whang) 대한전기학회 2019 전기학회논문지 Vol.68 No.1

This paper deals with the problem of generating the energy optimal trajectory which is intended to enhance the target tracking performance of a passive homing missile. Noticing that the essence of passive target tracking is the range estimation problem, the target information gathered by passive measurements can be readily analyzed by introducing the range estimator designed in line-of-sight(LOS) frame. Moreover, for the linear filter structure of the suggested range estimator, the cost function associated with the target information is clearly expressed as a function of the line-of-sight rate. Based on this idea, the optimal missile trajectory maximizing the target information is obtained by solving the saddle point problem for an indefinite quadratic cost which consists of the target information and the energy. It is shown that, different from the previous heuristic approaches, the guidance command producing the optimal passive homing trajectory is produced by the modified proportional navigation guidance law whose navigation constant is determined by the weighting coefficient for target information cost.