NEW METHOD FOR DESIGNING ROBUST ATTITUDE CONTROL LAW FOR FLEXIBLE LAUNCHERS APPLICATION TO ARIANE 5 E/CB

摘要

With the last evolution of future launchers, some characteristics, such as an increasing flexibility, make it more and more difficult to solve the launcher control problem during atmospheric flight We present in this paper a new method for designing robust attitude control law for flexible launchers whose first flexible mode is very close to the rigid mode frequency control, during atmospheric flight. This method is based on 3 steps : a coarse tuning of a simplified continuous SISO controller for the rigid mode, then, a MIMO optimisation of the rigid mode controller using H_∞ method and parametric optimisation and finally high frequency filtering. This method combines the simplicity of pole placement approach with the robustness and optimisation of H_∞ method. It has been successfully applied to a benchmark, opened to other industrials, on the flexible launcher Ariane 5 configuration E/CB.