Homing Trajectory Planning And Control For The Accurate Aerial Delivery Of Parafoil System

Parafoil system is widely used in the fields of military, aviation and aerospace to realize military supplies accurate aerial delivery and the spacecraft recycle mission, because of its controllability and long-distance gliding performance. Compared with the research of accurate aerial delivery system abroad, the domestic research is not mature enough recently. Focus on the research of parafoil precise airdrop system modeling, homing trajectory planning and controlling, the methods of theory analysis and numerical simulation are united in the thesis.Firstly, assume the fully inflated parafoil wing is rigid, to treat the whole parafoil-payload system as a single rigid body. Then a six-degrees-of-freedom model is established for the parafoil-payload system. Through Simulink model simulation,the fundamental movement characteristics of the parafoil-payload system is analyzed, which is the theoretical basis for homing trajectory planning and controlling in the next phase.Secondly, for the purpose of precise homing, the feasible airdrop region limited by the maneuverability and fundamental movement characteristics of the parafoil-payload system is studied. And because the solution of homing trajectory planning problem requires a simple, analytically tractable representation of the parofoil-payload system, a simplified steady-state model is constructed using only kinematic relationships and the parafoil steady-state performance data.Thirdly, based on the optimal control theory, the minimum-time, the minimum-control-energy, and the minimum-time-energy homing controlling are studied respectively. Then take altitude margin as the judging criterion of homing scheme and combine it with the certain advantages of each method for a more rational homing program.Finally, through simulation experiments, obtain the optimal homing trajectory and the related optimal control low under different altitude margins. Besides, the research work in this paper can not only realize precise airdrop under a limited condition, also can provide theoretical reference for other homing controlling methods.