Abstract:  In order to solve the longitudinal coordinated problem in the flight control system design of hypersonic flight vehicle, a coupling analysis is accomplished for the group of state variables, input variables, the group of path variables and attitude variables. A new hierarchical coordinated method of longitudinal system is presented based on quantitative coupling degree. The simulation results indicate that the control method, compared with the traditional control method, can effectively solve the problems of strong coupling between amongtrajectory motions, attitude motions and propulsion system, and realize more smooth and efficient trajectory tracking on the basis of keeping attitude stable.

Key words: hypersonic flight vehicle, coupling analysis, longitudinal model, coordinate control