Hierarchical Control Strategy for an Integrated Wastewater Treatment Plant

This paper presents the design of a hierarchical control system consisting of a model based centralized supervisory controller and a group of embedded controllers for a set of integrated biological reactors, which is a part of NASA’s advanced regenerative wastewater treatment system. A first principle model developed by [Zhang and Hoo, 2007] is used to design the centralized model predictive controller to regulate the performance of the integrated biological reactors for on-supply & ondemand operations simultaneously. The embedded control is implemented as safety mode to guarantee the process throughput performance in case of malfunction or the loss of communication with the higher level supervisory controller. The control design is implemented and tested on a testbed that is 1/20 the scale of the actual biological reactors.