Homing Trajectory Optimization And 3D Simulation Of Parafoil System

In recent years, parafoil delivery systems have been widely used in many aerospace scenarios, including military logistics, disaster rescue and also spacecraft recycling. The focus of this thesis includes two aspects. The first topic is to study the trajectory optimization during the aerial delivery process. The second topic is to build a three-dimensional computer simulation environment. The main work of this thesis can be summarized as follows.1. The structure and basic operation principle of parafoil system are introduced in this thesis. Then a 6-DoF mathematical model is reviewed to represent the dy-namics of parafoil system based on the force analysis during flight, which is fur-ther simplified for trajectory optimization.2. A trajectory optimal control problem for a simplified 3-DoF model of parafoil system is proposed. The optimization algorithm, which is based on time-scaling method and optimizes both control variables and knot points, is used to solve this problem. The simulation is implemented by using Matlab. The result shows that solving this optimal control problem with the time-scaling technique has a better performance compared to the piecewise constant control method, gradient decent method and other methods.3. The three-dimensional simulation of the parafoil system is developed by using hybrid programming with Matlab and VC++, to establish a virtual reality simula-tion environment. Furthermore, the Cognitive Robotics Architecture for Tightly-coupled Experiments and Simulation (CRATES) is established to improve the simulation effect. The description file of parafoil system is written and loaded in-to the CRATES simulation environment, which lays the foundation for the future work and study.