Multi-objective control of aerodynamically unstable launcher

This paper deals with the attitude stabilization problem of highly aerodynamically unstable launch vehicle during atmospheric phase. The autopilot design is characterized by classical requirements such as aero margin (AM), gain margin (GM), and phase margin (PM) as well as time-domain constraints on the response of angle of attack to a worst-case wind profile. These robustness requirements are difficult to meet during atmospheric phase when launcher is highly aerodynamically unstable. An autopilot has been designed by multi-objective control technique based on H_infin control theory for rigid body dynamics of launcher during high dynamic pressure region. To show the efficacy of the multi-objective controller, the design has been compared with an H_infin and classical controller.