• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.10
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• pp.996-1002
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• 2008

This paper presents the development of a real-time algorithm for collision detection, collision avoidance and guidance to way-point. Three-dimensional point-mass aircraft models are used. For collision detection, time of closest point of approach(CPA) and distance at CPA are compared to threshold values. For collision avoidance, optimal acceleration input which maximizes the terminal relative distance is calculated based on optimal control theory. For guidance to way-point, proportional navigation guidance, the well-known method, is used. Two scenarios of encounter situation are illustrated to validate performance of proposed algorithm.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.3
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• pp.153-162
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• 2016

This paper proposes an optimal dynamic resource allocation method in IoT (Internet of Things) parking guidance system using Q-learning resource allocation model. In the proposed method, a resource allocation using a forecasting model based on Q-learning is employed for optimal utilization of parking guidance system. To demonstrate efficiency and availability of the proposed method, it is verified by computer simulation and practical testbed. Through simulation results, this paper proves that the proposed method can enhance total throughput, decrease penalty fee issued by SLA (Service Level Agreement) and reduce response time with the dynamic number of users.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.10
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• pp.853-861
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• 2012

This paper considers one of the explicit guidance algorithms, which has been proposed by Jaggers, to determine the closed-loop guidance algorithm for upper stages of a 3-staged space launch vehicle. Its commanded thrust vector is closer to the optimal solution when compared with that obtained by using the well-known Powered Explicit Guidance (PEG), which has been developed through the Space Shuttle program. Its performance is evaluated here by applying for guidance of the launcher during the second and third stages. Furthermore, to generate more precise guidance commands, it is attempted not to use the approximate formulas for the derivation of the original guidance law, and it is shown that performance is improved in comparison with the original.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.47-52
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• 1998

This study deals with guidance and control laws for an optimal reentry trajectory of a vertical landing reusable launch vehicle (RLV) in the future. First, a guidance law is designed to create the reference trajectory which minimizes propellant consumption. Then, a nonlinear feedback controller based on a linear quadratic regulator is designed to make the vehicle follow the predetermined reference trajectory, The proposed method is simulated for the first stage of the H-II scale rocket.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.998-1001
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• 2009

This paper shows that the conventional proportional navigation guidance(PNG) law with a constant navigation gain is an optimal solution strictly also when the velocity is varying during engagement. Especially, PNG with navigation constant, 3, is an optimal solution minimizing a closing velocity weighted induced-drag. While most of previous studies on optimality of PNG were relied on the linear formulation and the constant speed assumption, this study presents more general analysis results on optimality of PNG based on the nonlinear formulation and the time-varying velocity assumption.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.4
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• pp.251-257
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• 2022

We formulated the convex optimization based minimum energy soft landing problem for reusable launch vehicles, and obtained the minimum time trajectory via the bisection search. In order to implement the the optimal guidance command and complete the flight control architectures on the soft landing stage, we designed the classical attitude control loops, and formulated and solved the optimal actuator allocation problem. The obtained soft landing guidance performance was analyzed via nonlinear 6-DOF simulation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.4
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• pp.367-371
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• 2009

Analysis on optimality of the proportional navigation guidance(PNG) law is presented in this paper. While most of previous studies on optimality of PNG were relied on the linear formulation, this paper is based on the nonlinear formulation. The analysis shows that PNG is an optimal solution minimizing a range-weighted control energy, where the weighting function is an inverse of $\alpha$ power of the distance-to-target. We show that the navigation constant N is related to $\alpha$ directly. And also the conditions required to ensure the analysis result are investigated.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.5
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• pp.52-58
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• 2011

The missile control system is comprised of various control systems such as autopilot, guidance law, and homing filter and so on. To design these guidance and control system, the optimization technique is widely applied at each developing stage. However, this kind of optimization requires lots of time and cost and moreover, this approach does not give an overall system optimization result. In this paper, to use the optimization tool for control system design, the optimal problem formulation is done and the performance index and constraints are considered. And finally the systematically optimized method is proposed.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.49-54
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• 2008

In order to do a maintenance task, a maintenance operator should learn the basic skills of the maintenance task such as assembly and disassembly (A/D). However, the key of the learning process is to learn the A/D task intuitively and naturally. Haptic guidance promises to give effectiveness and benefit qualitatively since a person can be trained to do the optimal task based on information that comes from an expert, database, or intelligent algorithms. By applying haptic guidance, a maintenance training process can be made more intuitive and natural in a virtual environment. This paper describes the development of a maintenance training system by using haptic guidance.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.222-224
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• 1995

This paper deals with 3-dimensional missile guidance law. This presents the general optimal solution of the state equation which includes the target maneuvering as the Gauss-Markov processing. The main results ore about the transformation between the Cartesian coordinates on which both the guidance law and the filter are bused and the polar coordinates system in real missile guidance and measurement information. And the extended Kalman filter and adjustment of the estimated target acceleration by triangular functions is proposed solution to this transformation problem. It is shown that this proposed transformation is valid in real 3-dimensional guidance problem by the computer simulation.