Hierarchical control system for recirculating aquaculture processes

In this paper a hierarchical control structure appropriated to recirculating aquaculture processes is proposed. The control software consists in two levels. The first level is the low level and deals with the basic control functions of the process such as: the control of the dissolved oxygen concentration and the temperature monitoring in the aquaculture tanks, the pH control after the mechanical treatment, the control of the water level in the tank located before the mechanical treatment etc. The second control level performs the following functions: the process diagnosis, the global control of the pilot plant for intensive fish growth in recycling regime, the balance of the system from the point of view of the recycling water flow, signaling damages etc. Besides the two control levels, the control application must contain a friendly graphical interface that allows the operator to observe the data or to intervene directly in the process through various commands.