Integrated design optimization of structural bending filter and gain schedules for rocket attitude control system

Abstract: This paper proposes an integrated design optimization framework for the gain schedules and bending filter for the longitudinal control of a rocket during its ascent flight. Dynamic models representing the pitch/yaw motion of a rocket considering the elements such as the rigid body dynamics, aerodynamics, sloshing, bending, sensor/actuator, and flight computer are introduced. The linear proportional and differential (PD) control law with scheduled (time-varying) gains and bending filter parameters are identified as key decision variables for stabilizing the pitch/yaw motion of the rocket. The integrated optimal design problem that determines the decision variables to minimize the worst-case peak associated with the first bending mode with constraints on the stability margins during the flight of the rocket is mathematically formulated. A case study on design of gain schedules and bending filter for an actual sounding rocket using the proposed framework is conducted to demonstrate its effectiveness.