Heterogeneous control and qualitative supervision, application to a distillation column
This paper addresses the following control problem: a continuous plant (P) is to be controlled via heterogeneous control law. The heterogeneous control laws apply even in the presence of incomplete knowledge of the system. This approach is based only on the knowledge of the physical boundaries of system input and output, and the maximum rate-of-change of the input. The qualitative values of the input, output, error and respective derivatives in a closed loop are used to recognise any characteristic dynamics such as: dead-time, damping, negative gain, inverse response and oscillations. The control actions are the result of qualitative operations concerning the magnitude and the derivative of error and a numeric operation to calculate the values of system input. Hence, the numeric and qualitative parts can be considered as a new approach to define a recurrent control law. These results are illustrated in a current application for the start-up and disturbance recovery of a distillation column.
heterogeneous control qualitative modelling qualitative simulation