Title of Paper:Modeling and control for ultra-low altitude cargo airdrop

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Affiliation of Author(s):航天学院

Journal:AIRCRAFT ENGINEERING AND AEROSPACE TECHNOLOGY

Key Words:Flight control H-infinity robust control Kane method Multi body system dynamics Ultra-low altitude heavy cargo airdrop

Abstract:Purpose - The purpose of this paper is to model the aircraft-cargo's coupling dynamics during ultra-low altitude heavy cargo airdrop and to design the aircraft's robust flight control law counteracting its aerodynamic coefficients perturbation induced by ground effect and the disturbance from the sliding cargo inside. Design/methodology/approach - Aircraft-cargo system coupling dynamics model in vertical plane is derived using the Kane method. Trimmed point is calculated when the cargo fixed in the cabin and then the approximate linearized motion equation of the aircraft upon it is derived. The robust stability and robust H-infinity optimal disturbance restraint flight control law are designed countering the aircraft's aerodynamic coefficients perturbation and the disturbance moment, respectively. Findings - Numerical simulation shows the effectiveness of the proposed control law with elevator deflection as a unique control input. Practical implications - The model derived and control law designed in the paper can be applied to heavy cargo airdrop integrated design and relevant parameters choice. Originality/value - The dynamics model derived is closed, namely, the model can be called in numerical simulation free of assuming the values of parachute's extraction force or cargo's relative sliding acceleration or velocity as seen in many literatures. The modeling is simplified using Kane method rather than Newton's laws. The robust control law proposed is effective in guaranteeing the aircraft's flight stability and disturbance restraint performance in the presence of aerodynamic coefficients perturbation.

ISSN No.:1748-8842

Translation or Not:no

Date of Publication:2018-01-01

Correspondence Author:Han Yanhua