Hybrid life extending control of mechanical structures

The goal of life extending control is to achieve high performance of complex dynamical systems (e.g., aircraft, spacecraft, and energy conversion systems) without overstraining the mechanical structures and the potential benefit is an increase in the service life of critical components with no significant loss of performance. The paper presents a two-tier architecture and a design methodology of hybrid (i.e., combined discrete-event and continuously-varying) life extending control for structural durability and high performance of mechanical systems. A feedback controller at the lower tier is designed with due consideration to robust performance and damage mitigation. A variable-structure stochastic automaton is employed at the lower tier for status evaluation of structural damage while the overall system performance is maintained by the supervisory level discrete-event controller at the upper tier. Experimental results on a laboratory test apparatus are presented for validation of the proposed concept of hybrid life extending control