Nonlinear Missile Autopilot Design with Θ - D Technique

Abstract

In this paper, a new nonlinear control method is used to design a full- envelope, hybrid bank-to-turn (BTT)/skid-to-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.

Department(s)

Mechanical and Aerospace Engineering

International Standard Serial Number (ISSN)

1533-3884; 0731-5090

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 American Institute of Aeronautics and Astronautics, All rights reserved.

Publication Date

01 Jan 2004

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