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A Missile Guidance Law Based on Sontag's Formula to Intercept Maneuvering Targets
Chang-Kyung Ryoo,Yoon-Hwan Kim,Min-Jea Tahk,Keeyoung Choi 대한전기학회 2007 International Journal of Control, Automation, and Vol.5 No.4
In this paper, we propose a nonlinear guidance law for missiles against maneuvering targets. First, we derive the equations of motion described in the line-of-sight reference frame and then we define the equilibrium subspace of the nonlinear system to guarantee target interception within a finite time. Using Sontag's formula, we derive a nonlinear guidance law that always delivers the state to the equilibrium subspace. If the speed of the missile is greater than that of the target, the proposed law has global capturability in that, under any initial launch conditions, the missile can intercept the maneuvering target. The proposed law also minimizes the integral cost of the control energy and the weighted square of the state. The performance of the proposed law is compared with the augmented proportional navigation guidance law by means of numerical simulations of various initial conditions and target maneuvers.
Kyung-Chang Ryoo,Jeong-Hoon Oh,Sunghun Jung,Sang Wan Kim,Min-Chul Sun,Garam Kim,Hyun Woo Kim,Dae Woong Kwon,Ji Soo Jang,Jang Hyun Kim,Hongsik Jeong,Byung-Gook Park 대한전자공학회 2010 ICEIC:International Conference on Electronics, Inf Vol.1 No.1
Relationships of resistive switching characteristics are investigated for NiO based Resistive Switching Random Access Memory (RRAM) by adapting cross-pointed structure. In order to evaluate high-density RRAM with low switching current, we have shown that there are important relationships between various analytical parameters and reset current reduction. We examine different initial switching behaviors and test various factors that cause them. Through these relationships, we confirm that significant reset current reduction is possible by controlling the initial cell fabrication process which results in stabilization of cell interface.
Alternative Capturability Analysis of PN Laws
Chang-Kyung Ryoo,Yoon-Hwan Kim,Min-Jea Tahk 한국항공우주학회 2006 International Journal of Aeronautical and Space Sc Vol.7 No.2
The Lyapunov stability theory has been known inadequate to prove capturability of guidance laws because the equations of motion resulted from the guidance laws do not have the equilibrium point. By introducing a proper transformation of the range state, the original equations of motion for a stationary target can be converted into nonlinear equations with a specified equilibrium subspace. Physically, the equilibrium subspace denotes the direction of missile velocity to the target. By using a single Lyapunov function candidate, capturability of several PN laws for a stationary target is then proved for examples. In this approach, there is no assumption of the constant speed missile. The proposed method is expected to provide a unified and simplified scheme to prove the capturability of various kinds of guidance laws.
Alternative Capturability Analysis of PN Laws
Ryoo, Chang-Kyung,Kim, Yoon-Hwan,Tahk, Min-Jea The Korean Society for Aeronautical and Space Scie 2006 International Journal of Aeronautical and Space Sc Vol.7 No.2
The Lyapunov stability theory has been known inadequate to prove capturability of guidance laws because the equations of motion resulted from the guidance laws do not have the equilibrium point. By introducing a proper transformation of the range state, the original equations of motion for a stationary target can be converted into nonlinear equations with a specified equilibrium subspace. Physically, the equilibrium subspace denotes the direction of missile velocity to the target. By using a single Lyapunov function candidate, capturability of several PN laws for a stationary target is then proved for examples. In this approach, there is no assumption of the constant speed missile. The proposed method is expected to provide a unified and simplified scheme to prove the capturability of various kinds of guidance laws.
OPTIMAL IMPACT ANGLE CONTROL GUIDANCE LAWS AGAINST A MANEUVERING TARGET
CHANG-KYUNG RYOO 한국산업응용수학회 2015 Journal of the Korean Society for Industrial and A Vol.19 No.3
Optimal impact angle control guidance law and its variants for intercepting a maneuvering target are introduced in this paper. The linear quadratic(LQ) optimal control theory is reviewed first to setup framework of guidance law derivation, called the sweep method. As an example, the inversely weighted time-to-go energy optimal control problem to obtain the optimal impact angle control guidance law for a fixed target is solved via the sweep method. Since this optimal guidance law is not applicable for a moving target due to the angle mismatch at the impact instant, the law is modified to three different biased proportional navigation(PN) laws: the flight path angle control law, the line-of-sight(LOS) angle control law, and the relative flight path angle control law. Effectiveness of the guidance laws are verified via numerical simulations.