Multi-phase Trajectory Optimization for a Hypersonic Vehicle

A new approach was proposed to solve multi-phase trajectory optimization problem.The approach allowed the trajectory for hypersonic vehicle in vertical plane dividing into several phase,then obtaining the multi-phase trajectory optimal value by MDO method.In this paper,only the transitional phase,gliding phase and descending phase were investigated.The expectation was that the terminal velocity maximum in transitional phase,the range maximum in gliding phase and the flight time minimum in descending phase.The three phase was regarded as three discipline,and the attack angle and initial condition were as input and terminal condition as output for every discipline,then the sensitivity of output to input in every phase was computed.Then the global sensitivity of index to every design variables was obtained by solving global sensitivity equation.Lastly optimal step in the direction of global sensitivity and optimal value was achieved by optimizing and computing.The results showed that the computing efficiency of GSE method had been higher than all-in-one method.