Damage-Mitigating Control of Mechanical Systems: Part II—Formulation of an Optimal Policy and Simulation

The objective of damage-mitigating control introduced in the first part of this two-part paper is to achieve high performance without overstraining the mechanical structures. The major benefit is an increase in the functional life of critical plant components along with enhanced safety, operational reliability, and availability. Specifically, a methodology for modeling fatigue damage has been developed as an augmentation to control and diagnostics of complex dynamic processes such as advanced aircraft, spacecraft, and power plants. In this paper which is the second part, an optimal control policy is formulated via nonlinear programming under specified constraints of the damage rate and accumulated damage. The results of simulation experiments for upthrust transient operations of a reusable rocket engine are presented to demonstrate efficacy of the damage-mitigating control concept.