Control design decoupling for two-way coupled systems

Many systems are made up of a number of interacting subsystems, with multiple performance specifications to be met. For such systems, the control system design becomes a challenging task. Conventional engineering process follows a bottom-up approach, where the subsystem controllers are designed independently, and then the subsystems are assembled. Unaccounted for interactions are then handled by ad-hoc troubleshooting methods, which may compromise the original design specifications. We present a design decoupling method such that the resulting closed-loop system and its overall system performance is achieved by the subsystem controller implementation. The subsystem controller design is treated as if they are independent. Therefore, the system integration process is straight forward and the performance (including subsystem interactions) has been systematically addressed.