Using Modified IPSO-SQP Algorithm to Solve Nonlinear Time Optimal Bang-bang Control Problem

In this paper, an intelligent-gradient based algorithm is proposed to solve time optimal bang-bang control problem. the proposed algorithm is a combination of an intelligent algorithm called improved particle swarm optimization algorithm (ipso) in the first stage of optimization process together with a gradient-based algorithm called successive quadratic programming method (sqp) in the second stage. the proposed algorithm is called mipso-sqp algorithm which in essence is a modification of the previous ipso-sqp algorithm (pipso-sqp). new steps in optimization process of the proposed mipso-sqp algorithm causes the algorithm to reach to global optimal solution regardless of any guess of the initial control input and/or the number of switching. validity of results is verified through adding some arcs to present arcs. the proposed algorithm is successfully applied in time optimal bang-bang control of the van der pol equations, rayleigh system and f8 aircraft model. a comparison study is also performed to assess the performance of mipso-sqp with respect to switching time optimal method (tos), mathematical programming method and pipso-sqp algorithm. it is shown that mipso-sqp algorithm is more effective than these algorithms due to ability to find global optimum solution in less iteration and in a more systematic way