A parameter optimization approach to controller partitioning for integrated flight/propulsion control application

A parameter optimization framework is presented to solve the problem of partitioning a centralized controller into a decentralized hierarchical structure suitable for integrated flight/propulsion control implementation. The controller partitioning problem is discussed and a cost function to be minimized is formulated, such that the resulting optimal partitioned subsystem controllers closely match the performance (including robustness) properties of the closed-loop system with the centralized controller while maintaining the desired controller partitioning structure. The cost function is written in terms of parameters in a state-space representation of the partitioned subcontrollers. Analytical expressions are obtained for the gradient of this cost function with respect to parameters and an optimization algorithm is developed using modern computer-aided control design and analysis software. The capabilities of the algorithm are demonstrated by application to partitioned integrated flight/propulsion control design for a modern fighter aircraft in the short approach to landing task. The partitioning optimization leads to reduced-order subcontrollers that match the closed-loop command tracking and decoupling performance achieved by a high-order centralized controller