Ascent phase trajectory optimization for aircraft based on Nonlinear Programming

Ascent phase minimum time-to-climb trajectory optimization problem(TOP) is studied in the paper. To avoid the drawback of indirect methods and traditional direct methods, a new optimal control method-Gauss Pseudospectral Method(GPM) was used to transform the trajectory optimization problem into Nonlinear Program(NLP) problem. A initial guess strategy was proposed to improve the convergence rate of NLP problem, based on the guess, which can be solved using a sparse nonlinear optimization software named SNOPT. The optimality of the solution was verified via checking up the Hamiltonian function. Finally, simulation results demonstrate the efficiency of the method.