On specific optimal control of systems with different information sets

The problem of reduced-order, observer-based control of systems with controllers having different information about the system is considered. The set of necessary conditions for optimality is obtained, and then the breakdown of the separation principle is demonstrated. The necessary conditions are simplified, and it is shown that a suboptimal control law based on separation can be obtained to satisfy the necessary conditions.The author is indebted to Professor C. T. Leondes for his continuous support, guidance, and stimulating discussions.