Robust control of a launch vehicle in atmospheric ascent based on guardian maps

A robust control design for a space launcher during its atmospheric ascent is presented. Considering a typical wind profile during flight, the launcher controller has to first stabilize the open-loop unstable system, and then maintain verticality. The model available takes into account flexible modes and nozzle actuator dynamics, and is time-variant. Aside from launcher stability, additional requirements pertaining to frequency and damping of rigid launcher modes as well as flexible ones, must be fulfilled. The synthesis relies on guardian maps, making possible to characterize the sets of all controller gains which meet the requirements, by specifying areas of interest where the system's closed-loop poles must be located.