Analysis And Optimization Of An Aerial Refueling Hose & Drogue System In Deployment And Retrieval Process

In the deployment and retrieval process of refueling hose, the actual working environment of hose is severe, it may cause the output speed of motor unstable, so that the hose goes into unstable motion, leading to the crawling and trembling of the hose and drogue. To improve the dynamic response characteristics of hose in the deployment and retrieval process, the speed control of hose can be optimized. The model was established using multi-body dynamics in which process the hose was modeled as discrete particle system connected through a series of massless rigid rod, while the deployment and retrieval process of refueling hose was simulated through changing the properties of the cell which nearest the pod and adding or removing a cell which nearest the pod at the appropriate time. Using this mathematical model, the effect of bending recovering force on dynamic property of hose and drogue system during the deployment and retrieval process is analyzed. In pure tension control situation, a direct shooting method based on discretization of the hose length is proposed to optimize real-time freedom model of hose and drogue system and its trajectories of deployment and retrieval process. The target function is minimizing the acceleration square of length change of hose. Chebyshev polynomial is used in interpolation of hose length. Lagrange multipliers are used to reduce the optimization variables. To overcome the initial value sensitivity characteristics of direct shooting method, a more robust optimization method, genetic algorithm, is used to get a staring guess. And then quasi-Newton method is used to get the optimal solution. The simulation results show that the methodology in this paper to optimizing the trajectory design has good robustness and convergence.