Applying Nonlinear Programming to Solve Optimal Control Problem of Lunar Probe Soft Landing

A method of applying nonlinear program to solve optimal control problem of lunar probe soft landing under finite thrust is studied. Based on Pontryagin maximum principle, the lunar soft landing problem is transformed into a two-point boundary value problem. Considering bound condition and transversality condition, the resulted two-point boundary value problem is converted into parameters optimization problem aiming at the initial values of conjugate variables which is solved by nonlinear programming. The result of the simulation demonstrates the proposed design scheme is simple and effective.