Damage mitigating control of a reusable rocket engine for structural durability

The goal of damage mitigating control is to achieve a desired level of trade-off between structural durability of critical component(s) and overall dynamic performance of the plant (e.g., aircraft, spacecraft, and energy conversion systems). The paper presents the synthesis of damage-mitigating output feedback controllers and applies this method to a reusable rocket engine by taking fatigue crack damage of turbine blades into consideration. The effects of crack growth retardation due to overload are included in the fatigue damage model which is formulated in the state-space setting. Simulation results are presented to demonstrate the effectiveness of the damage-mitigating control concept.