• Title/Summary/Keyword: Missile Autopilot

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Integrated Roll-Pitch-Yaw Autopilot via Equivalent Based Sliding Mode Control for Uncertain Nonlinear Time-Varying Missile

  • AWAD, Ahmed;WANG, Haoping
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.4
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    • pp.688-696
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    • 2017
  • This paper presents an integrated roll-pitch-yaw autopilot using an equivalent based sliding mode control for skid-to-turn nonlinear time-varying missile system with lumped disturbances in its six-equations of motion. The considered missile model are developed to integrate the model uncertainties, external disturbances, and parameters perturbation as lumped disturbances. Moreover, it considers the coupling effect between channels, the variation of missile velocity and parameters, and the aerodynamics nonlinearity. The presented approach is employed to achieve a good tracking performance with robustness in all missile channels simultaneously during the entire flight envelope without demand of accurate modeling or output derivative to avoid the noise existence in the real missile system. The proposed autopilot consisting of a two-loop structure, controls pitch and yaw accelerations, and stabilizes the roll angle simultaneously. The Closed loop stability is studied. Numerical simulation is provided to evaluate performance of the suggested autopilot and to compare it with an existing autopilot in the literature concerning the robustness against the lumped disturbances, and the aforesaid considerations. Finally, the proposed autopilot is integrated in a six degree of freedom flight simulation model to evaluate it with several target scenarios, and the results are shown.

Study on Missile Aerodynamic Characteristics with Three Loop Acceleration Autopilot Structure (3-루프 가속도 오토파일롯 구조를 갖는 유도탄의 공력특성 연구)

  • Kim, Yoon-Sik;Kim, Seung-Hwan
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.8
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    • pp.633-638
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    • 2002
  • We study how the missile autopilot with three loop acceleration structure is related to the aerodynamic characteristics. First, the relationships between the response characteristics of wingless-tail controlled missile and aerodynamics are derived. Next the maximum allowable performance limit of autopilot and the design direction for a missile shape are indicated using the property of zero. The method proposed in this paper may give a help to the missile autopilot system design and determination of the shape of aerodynamic. Also, the validity of proposed method is demonstrated via numerical example.

Design of an improved STT missile digital autopilot with respect to sampling time (샘플링 시간에 대해 개선된 Singular Perturbation 기반 STT missile 디지털 autopilot 설계)

  • 정선태
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.468-471
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    • 1997
  • In this paper, we investigate the time-sampling effects on the digital implementation of singular perturbation based STT autopilot with excellent performance and propose a compensation method for the time-sampling effects. In digitization of analog STT autopilot, it is found that the stability margin of the fast dynamics is mostly affected to lead to rapid decrease. Under the this analysis, a composite digital controller with additional compensator for fast dynamics is proposed to improve the time-sampling effect and a simulation verifies the result.

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Adaptive control to compensate the modeling error of STT missile (STT 미사일의 모델링 오차 보상을 위한 적응 제어)

  • 최진영;좌동경
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1292-1295
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    • 1996
  • This paper proposes an adaptive control technique for the autopilot design of STT missile. Dynamics of the missile is highly nonlinear and the equilibrium point is vulnerable to change due to fast maneuvering. Therefore nonlinear control techniques are desirable for the autopilot design of the missile. The nonlinear controller requires the exact model to obtain satisfactory performance. Generally a look-up table is used for the dynamic coefficients of a missile, so there must be coefficients error during actual flight, and the performance of the nonlinear controller using these data can be degraded. The proposed adaptive control technique compensates the nonlinear controller with modeling error resulting from the error of aerodynamic data and disturbance. To investigate the usefulness, the proposed method is applied to autopilot design of STT missile through simulations.

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A New Approach to Motion Modeling and Autopilot Design of Skid-To-Turn Missiles

  • Chanho Song;Kim, Yoon-Sik
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.3
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    • pp.231-238
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    • 2002
  • In this paper, we present a new approach to autopilot design for skid-to-turn missiles which may have severe aerodynamic cross-couplings and nonlinearities with angle of attack. The model of missile motion is derived in the maneuver plane and, based on that model, pitch, yaw, and roll autopilot are designed. They are composed of a nonlinear term which compensates for the aerodynamic couplings and nonlinearities and a linear controller driven by the measured outputs of missile accelerations and angular rates. Besides the outputs, further information such as Mach number, dynamic pressure, total angle of attack, and bank angle is required. With the proposed autopilot and simple estimators of bank angle and total angle of attack, it is shown by computer simulations that the induced moments and some aerodynamic nonlinearities are properly compensated and that the performance is superior to that of the conventional ones.

Missile Autopilot Design for Agile Turn Using Time Delay Control with Nonlinear Observer

  • Lee, Chang-Hun;Kim, Tae-Hun;Tahk, Min-Jea
    • International Journal of Aeronautical and Space Sciences
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    • v.12 no.3
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    • pp.266-273
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    • 2011
  • This paper deals with missile autopilot design for agile turn phase in air-to-air engagement scenarios. To attain a fast response, angle-of-attack (AOA) is adopted for an autopilot command structure. Since a high operational AOA is generally required during the agile turn phase, dealing with the aerodynamic uncertainties can be a challenge for autopilot design. As a remedy, a new controller design method based on robust nonlinear control methodology such as time delay control is proposed in this paper. Nonlinear observer is also proposed to estimate the AOA in the presence of the model uncertainties. The performance of the proposed controller with variation of the aerodynamic coefficients is investigated through numerical simulations.

Missile Adaptive Control using T-S Fuzzy Model (T-S 퍼지 모델을 이용한 유도탄 적응 제어)

  • 윤한진;박창우;박민용
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2001.12a
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    • pp.129-132
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    • 2001
  • In this paper, in order to control uncertain missile autopilot, an adaptive fuzzy control(AEC) scheme via parallel distributed compensation(PDC) is developed for the multi-input/multi-output plants represented by the Takagi-Sugeno(T-S) fuzzy model. Moreover adaptive law is designed so that the plant output tracks the stable reference model(SRM), From the simulations results, we can conclude that the suggested scheme can effectively solve the control problems of uncertain missile systems based on T-S fuzzy model.

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Autopilot Design for Agile Missile with Aerodynamic Fin and Thrust Vecotring Control

  • Lee, Ho-Chul;Choi, Yong-Seok;Choi, Jae-Weon
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.525-530
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    • 2003
  • This paper is concerned with a control allocation strategy using the dynamic inversion which generates the nominal control input trajectories, and autopilot design using the time-varying control technique which is time-varying version of pole placement of linear time-invariant system for an agile missile with aerodynamic fin and thrust vectoring control. Dynamic inversion can decide the amount of the deflection of each control effector, aerodynamic fin and thrust vectoring control, to extract the maximum performance by combining the action of them. Time-varying control technique for autopilot design enhance the robustness of the tracking performance for a reference command. Nonlinear simulations demonstrates the dynamic inversion provides the effective nominal control input trajectories to achieve the angle of attack command, and time-varying control technique exhibits good robustness for a wide range of angle of attack.

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Application of nonlinear control via output redefinition to missile autopilot (출력재정의를 통한 비선형제어 기법의 미사일 오토파일롯 응용)

  • 류진훈;탁민제
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1496-1499
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    • 1996
  • A nonlinear tracking control technique developed for the control of nonlinear systems has been applied to the autopilot design of missile system. The difficulties in the application of inversion based control methods such as input-output feedback linearization and sliding mode control due to nonminimum phase characteristics are discussed. To avoid the stability problem associated with unstable zero dynamics, the input-output feedback linearization is applied with output-redefinition method to normal acceleration control. The output-redefinition method gives an indirect way to apply the nonlinear controls to nonminimum phase plants by redefining the plant output such that the tracking control of the modified output ensures the asymptotic tracking of the original output. The numerical simulation shows satisfactory results both for nominal and for slightly perturbed missile systems adopting the sliding mode control technique. However, the robustness problem in this method is briefly investigated and verified with the simulation.

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Design of an Autopilot for the BTT Missile using 2DOF Wiener-Hopf Methods (2자유도 위너-호프 제어기법을 이용한 BTT 유도탄의 자동조종장치 설계)

  • Min, Deuk-Gi;Lee, Jong-Sung;Park, Ki-Heon
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.569-572
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    • 1999
  • This paper presents a method for designing an autopilot of the BTT missile using 2DOF Wiener-Hopf control technique to improve tracking performance. Linear controllers are designed based on the linearized models which are obtained from the nonlinear missile dynamic equations at various operating points. The gain scheduling technique is used to implement the final autopilot. A simulation on the flight of missiles is carried out through the use of 6DOF equation program including exact nonlinear equations of the missile and the variations of aerodynamic variables in order to check applicability of the suggested method in real situation.

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