Hypersonic reentry trajectory optimization by using improved sparrow search algorithm and control parametrization method.

A constrained hypersonic reentry trajectory optimization problem is formulated and solved using a hybrid algorithm. The hypersonic reentry trajectory optimization problem is transformed into a parametric optimization problem by the control parameterization method, and the penalty function approach is used to solve path constraints and terminal constraints. To reduce the sensitivity of the initial value of the control parameterization method, the improved sparrow search algorithm is proposed as an initial value generator to obtained an excellent initial solution. The initial solution generation efficiency and global optimality are enhanced by applying the Tent chaotic sequence mapping and the golden sine update strategy. Numerical simulations of test functions demonstrate that the proposed approach has fast convergence speed and excellent accuracy when compared with other typical optimization algorithm. The results of hypersonic reentry simulations indicate that the proposed approach is effective and has good robustness. [ABSTRACT FROM AUTHOR]