CAJ | 학술논문

A modified direct optimization method is proposed to solve the optimal muhi-revolution transfer with low-thrust between Earth-orbits. First, through parametefizing the control steering angles by costate variables, the search space of free parameters has been decreased. Then, in order to obtain the global optimal solution ef-fectively and robustly, the simulated annealing and penalty function strategies were used to handle the con-straints, and a GA/SQP hybrid optimization algorithm was utilized to solve the parameter optimization problem, in which, a feasible suboptimal solution obtained by GA was submitted as an initial parameter set to SQP for re-finement. Comparing to the classical direct method, this novel method has fewer free parameters, needs not ini-tial guesses, and has higher computation precision. An optimal-fuel transfer problem from LEO to GEO was taken as an example to validate the proposed approach. The results of simulation indicate that our approach is a-vailable to solve the problem of optimal multi-revolution transfer between Earth-orbits.