• Title/Summary/Keyword: IGC

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Integrated Guidance and Control Law with Impact Angle Constraint (입사각제어를 위한 통합유도조종법칙)

  • Yun, Joong-Sup;Park, Woo-Sung;Ryoo, Chang-Kyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.6
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    • pp.505-516
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    • 2011
  • The concept of the IGC(Integrated Guidance and Control) has been introduced to overcome the performance limit of the SGC(Separated Guidance and Control) loop. A new type of IGC with impact angle constraint has been proposed in this paper. Angle of attack, pitch angle rate, pitch angle and line of sight angle are considered as state variables. A controllability analysis and equilibrium point analysis have been carried out to investigate the control characteristic of the prposed IGC. The LQR(Linear Quadratic Regulator) has been adopted for the control law and detailed explanations about the adoption has been provided. The performance comparison between the IGC and the SGC has been carried out. The result of numerical simulations shows that the IGC guarantees better guidance performance than the SGC when the agile maneuver is needed for a specific guidance geometry.

A Study on Modified IGC Algorithm for Realtime Noise Reduction (실시간 소음 제거에 적합한 변형 IGC 알고리즘에 관한 연구)

  • Lee, Chae-Wook
    • Journal of the Institute of Convergence Signal Processing
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    • v.14 no.2
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    • pp.95-98
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    • 2013
  • The LMS(Least Mean Square) algorithm, one of the most famous, is generally used because of tenacity and high mating spots and simplicity of realization, But it has trade-off between nonuniform collection and EMSE(Excess mean square error). To overcome this weakness, a variable step size is used widely, but it needs a lot of calculation loads. In this paper, we suggest changed algorithm in case of environment changes of cars and reduce amount of calculation as it uses original signal and noise signal of IGC(Instantaneous Gain Control) algorithm. In this paper, logarithmic function is removed because of real-time processing IGC. The performance of proposed algorithm is tested to adaptive noise canceller in automobile.

Labview FPGA Implementation of IGC Algorithm for Real Time Noise Cancelation (실기간 소음제거를 위한 IGC Algorithm의 LabVIEW FPGA 구현)

  • Kim, Chun-Sik;Lee, Chae-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.3C
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    • pp.183-189
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    • 2011
  • The LMS(Least Mean Square) algorithm is generally used because of tenacity, high mating spots and simplicity of realization. But the LMS algorithm has trade-off between nonuniform collect and EMSE(Excess Mean Square Error). To overcome this weakness, variable step size is used widely but it needs a lot of calculation load. In this paper we consider new algorithm, which can reduce calculations and adapt in case of environment changes, uses original signal and noise signal of IGC(Instantaneous Gain Control). For the real time processing of IGC algorithm, we remove the logarithmic function. The performance of proposed algorithm is tested to adaptive noise canceller in automobile. We show implemented LabVIEW FPGA system of IGC algorithm is more efficient than others.

Effects of Convection Gas on Formation of Sn Oxide Nanoparticles (Sn 산화물 나노입자 형성에 미치는 대류 가스의 영향)

  • ;;;K. Niihara
    • Journal of Powder Materials
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    • v.9 no.1
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    • pp.32-37
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    • 2002
  • In the present study of IGC (Inert Gas Condensation) evaporation-condensation processing study, the effects of IGC convection gas on the crystallographic structure, size and shape of tin oxide nanoparticles were investigated. In addition, the phase transformation of tin oxide nanoparticles was studied after heat treatment. IGC processing was conducted at 1000℃ for 1 hr. The mixture gas of oxygen and helium was used as a convection gas. Metastable tetragonal SnO nanoparticles were obtained at a lower convection gas pressure, whereas amorphous tin oxide nanoparticles were obtained at a higher one. The formation of amorphous phase could be explained by the rapid quenching of the vaporized atoms. The resultant nanoparticles size was about 10 nm with a rounded shape. The tin oxide nanoparticles prepared by IGC were almost transformed to the stable tetragonal SnO₂ after heat treatment.

Integrated Guidance and Control Design for the Near Space Interceptor

  • WANG, Fei;LIU, Gang;LIANG, Xiao-Geng
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.2
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    • pp.278-294
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    • 2015
  • Considering the guidance and control problem of the near space interceptor (NSI) during the terminal course, this paper proposes a three-channel independent integrated guidance and control (IGC) scheme based on the backstepping sliding mode and finite time disturbance observer (FTDO). Initially, the three-channel independent IGC model is constructed based on the interceptor-target relative motion and nonlinear dynamic model of the interceptor, in which the channel coupling term and external disturbance are regarded as the total disturbances of the corresponding channel. Then, the FTDO is introduced to estimate the target acceleration and control system loop disturbances, and the feed-forward compensation term based on the estimated values is employed to effectively remove the effect of disturbances in finite time. Subsequently, the IGC algorithm based on the backstepping sliding mode is also given to obtain the virtual control moment. Furthermore, a robust least-squares weighted control allocation (RLSWCA) algorithm is employed to distribute the previous virtual control moment among the corresponding aerodynamic fins and reaction jets, which also takes into account the uncertainty in the control effectiveness matrix. Finally, simulation results show that the proposed IGC method can obtain the small miss distance and smooth interceptor trajectories.

Implementation of Adaptive Noise Canceller with Instantaneous Gain (순시 이득을 이용한 적응잡음제거기 구현)

  • Lee, Jae-Kyun;Kim, Chun-Sik;Lee, Chae-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.8C
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    • pp.756-763
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    • 2009
  • The Least Mean Square (LMS) algorithm is often used to restore signal corrupted by additive noise. A major defect of this algorithm is that the excess Mean Square Error (EMSE) increases linearly according to speech signal power. This result reduces the efficiency of performance significantly due to the large EMSE around the optimum value. Choosing a small step size solves this defect but causes a slow rate of convergence. The step size must be optimized to satisfy a fast rate of convergence and minimize EMSE. In this paper, the Instantaneous Gain Control (IGC) algorithm is proposed to deal with the situation as it exists in speech signals. Simulations were carried out using a real speech signal combined with Gaussian white noise. Results demonstrate the superiority of the proposed IGC algorithm over the LMS algorithm in rate of convergence, noise reduction and EMSE.

Integrated Design of Rotary UAV Guidance and Control Systems Utilizing Sliding Mode Control Technique

  • Hong, You-Kyung;Kim, You-Dan
    • International Journal of Aeronautical and Space Sciences
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    • v.13 no.1
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    • pp.90-98
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    • 2012
  • In this paper, the Integrated Guidance and Control (IGC) law is proposed for the Rotary Unmanned Aerial Vehicle (RUAV). The objective of the IGC law is to consider the nonlinear dynamic characteristics of the RUAV and to design a guidance law which takes into consideration the nonlinear relationship between kinematics and dynamics. In order to control the RUAV system, sliding mode control scheme is adopted. As the RUAV is an under-actuated system, a slack variable approach is used to generate the available control inputs. Through the Lyapunov stability theorem, the stability of the proposed IGC law is proved. In order to verify the performance of the IGC law, numerical simulations are performed for waypoint tracking missions.