The Experts below are selected from a list of 9933 Experts worldwide ranked by ideXlab platform
Mario Innocenti - One of the best experts on this subject based on the ideXlab platform.
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a sliding mode missile pitch Autopilot synthesis for high angle of attack maneuvering
IEEE Transactions on Control Systems and Technology, 1998Co-Authors: A Thukral, Mario InnocentiAbstract:A new approach to the synthesis of longitudinal Autopilots for missiles flying at high angle of attack regimes is presented. The methodology is based on sliding mode control, and uses a combination of aerodynamic surfaces and reaction jet thrusters, to achieve controllability beyond stall. The Autopilot is tested on a small section of the flight envelope consisting of a fast 180/spl deg/ heading reversal in the vertical plane, which requires robustness with respect to uncertainties in the system's dynamics induced by large variations in dynamic pressure and aerodynamic coefficients. Nonlinear simulation results show excellent performance and capabilities of the control system structure.
Ernest Ohlmeyer - One of the best experts on this subject based on the ideXlab platform.
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nonlinear missile Autopilot design with theta d technique
Journal of Guidance Control and Dynamics, 2004Co-Authors: Ming Xin, S N Balakrishnan, Donald T Stansbery, Ernest OhlmeyerAbstract:In this paper, a new nonlinear control method is used to design a full-envelope, hybrid bank-to-turn (BTT)/skidto-turn (STT) Autopilot for an airbreathing air-to-air missile. Through this new approach, called the θ − D method, we find approximate solutions to the Hamilton‐Jacobi Bellman (HJB) equation. As a result, the resulting nonlinear feedback law can be expressed in a closed form. In this paper, a θ − D outer-loop and inner-loop controller structure is used in an Autopilot design. A hybrid BTT/STT Autopilot command logic is used to convert the commanded accelerations from the guidance laws to reference angle commands for the Autopilot. The outer-loop θ − D controller converts the angle-of-attack, sideslip, and bank-angle commands to body-rate commands for the inner loop. An inner-loop θ − D controller converts the body-rate commands to fin commands. This design is evaluated using a detailed six-degrees-of-freedom simulation. Numerical results show that the new controllers achieve excellent tracking performance and exhibit insensitivity to parameter variations over a wide flight envelope.
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integrated design of agile missile guidance and Autopilot systems
Control Engineering Practice, 2001Co-Authors: P K Menon, Ernest OhlmeyerAbstract:Abstract Traditional approach for the design of missile guidance and Autopilot systems has been to design these subsystems separately and then to integrate them. Such an approach does not exploit any beneficial relationships between these and other subsystems. A technique for integrated design of missile guidance and Autopilot systems using the feedback linearization technique is discussed. Numerical results using a six degree-of-freedom missile simulation are given. Integrated guidance-Autopilot systems are expected to result in significant improvements in missile performance, leading to lower weight and enhanced lethality. These design methods have extensive applications in high performance aircraft Autopilot and guidance system design.
A Thukral - One of the best experts on this subject based on the ideXlab platform.
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a sliding mode missile pitch Autopilot synthesis for high angle of attack maneuvering
IEEE Transactions on Control Systems and Technology, 1998Co-Authors: A Thukral, Mario InnocentiAbstract:A new approach to the synthesis of longitudinal Autopilots for missiles flying at high angle of attack regimes is presented. The methodology is based on sliding mode control, and uses a combination of aerodynamic surfaces and reaction jet thrusters, to achieve controllability beyond stall. The Autopilot is tested on a small section of the flight envelope consisting of a fast 180/spl deg/ heading reversal in the vertical plane, which requires robustness with respect to uncertainties in the system's dynamics induced by large variations in dynamic pressure and aerodynamic coefficients. Nonlinear simulation results show excellent performance and capabilities of the control system structure.
Minjea Tahk - One of the best experts on this subject based on the ideXlab platform.
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roll pitch yaw integrated μ synthesis for high angle of attack missiles
Aerospace Science and Technology, 2012Co-Authors: Byunghun Choi, Minjea Tahk, Seonhyeok Kang, Jin H Kim, Byungeul Jun, Jinik Lee, Changhan ParkAbstract:Abstract In this research, we explore the feasibility of a roll-pitch-yaw integrated Autopilot for a high angle-of-attack missile. Investigation of the aerodynamic characteristics of a surface-to-air missile is presented, which reveals the strong effects of aerodynamic cross-coupling between the longitudinal and lateral dynamics. Robust control techniques based on H ∞ and μ-synthesis are employed to design roll-pitch-yaw integrated Autopilots. The performance of the proposed roll-pitch-yaw integrated controller is tested in nonlinear simulation accounting for cross-coupling effects between the lateral and longitudinal channels. In comparison of H ∞ and μ controllers, the performance of μ controller is slightly better in terms of rising time and settling time of the response. Using μ analysis, we identified the suitable structure and magnitude of the uncertainty block representing the nonlinear perturbations and cross coupling in the missile dynamics. The level of robustness obtained cannot be achieved by a controlled designed in a decoupled manner.
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multi model approaches to three axis missile Autopilot design under aerodynamic roll angle uncertainty
Proceedings of the Institution of Mechanical Engineers Part G: Journal of Aerospace Engineering, 2012Co-Authors: Minjea TahkAbstract:The problem of designing a robust three-axis missile Autopilot that operates under aerodynamic roll angle uncertainty is addressed in this article. A finite number of local state-space models over an aerodynamic roll angle envelope are developed as a multi-model to represent uncertainty bounds. Two design methods with multi-objective output-feedback control are proposed. In the first approach, a classical three-loop Autopilot structure is slightly modified for the multivariable Autopilot design. The optimal gains in the Autopilot structure are automatically obtained by using a co-evolutionary optimization method that addresses competing specifications and constraints. In the second approach, the mixed H2/H∞ performance criteria are guaranteed by multi-objective control synthesis via optimization techniques. Both design approaches are used in non-linear simulations with variations in the aerodynamic roll angle to provide satisfactory performance as a three-axis missile Autopilot.
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three axis Autopilot design for a high angle of attack missile using mixed h 2 h control
International Journal of Aeronautical and Space Sciences, 2010Co-Authors: Daeyeon Won, Minjea Tahk, Yoonhwan KimAbstract:We report on the design of a three-axis missile Autopilot using multi-objective control synthesis via linear matrix inequality techniques. This Autopilot design guarantees H₂/H ∞ performance criteria for a set of finite linear models. These models are linearized at different aerodynamic roll angle conditions over the flight envelope to capture uncertainties that occur in the high-angle-of-attack regime. Simulation results are presented for different aerodynamic roll angle variations and show that the performance of the controller is very satisfactory.
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high angle of attack missile Autopilot design by pole placement approach
International Symposium on Systems and Control in Aeronautics and Astronautics, 2010Co-Authors: Minjea TahkAbstract:This paper presents the missile Autopilot design for 180° heading reversal maneuver. For this purpose, angle of attack controller using pole placement approach is designed. The three Autopilot gains can be computed from aerodynamic coefficients and three design parameters to satisfy some designer-chosen criteria. Design parameters are closed-loop frequency, damping ratio, and time constant, representing the characteristics of control system. To deal with nonlinear control problems in high angle of attack missile, gain scheduled technique is employed. The simulation results validate performances and capabilities of the control system.
P K Menon - One of the best experts on this subject based on the ideXlab platform.
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integrated design of agile missile guidance and Autopilot systems
Control Engineering Practice, 2001Co-Authors: P K Menon, Ernest OhlmeyerAbstract:Abstract Traditional approach for the design of missile guidance and Autopilot systems has been to design these subsystems separately and then to integrate them. Such an approach does not exploit any beneficial relationships between these and other subsystems. A technique for integrated design of missile guidance and Autopilot systems using the feedback linearization technique is discussed. Numerical results using a six degree-of-freedom missile simulation are given. Integrated guidance-Autopilot systems are expected to result in significant improvements in missile performance, leading to lower weight and enhanced lethality. These design methods have extensive applications in high performance aircraft Autopilot and guidance system design.