Patent Document ID: 5572420
Application ID: 08415881
Patent Flag: 1

Claim One:
1. In a process control system having a controller for providing robust control to a process, the process further having at least one manipulated variable and at least one process variable, a method for providing the robust control of a process, comprising the steps of: a) loading the controller with parameters which define an optimal controller, the parameters calculated off-line including the steps of: i) defining a single min-max statement for a worst case model of the process to operate in conjunction with the controller having a best case; ii) converting said single min-max statement to a corresponding minimization expression, the corresponding minimization expression being a canonical of the single min-max statement; and iii) solving the minimization problem yielding a resultant solution, the resultant solution being the parameters; b) initializing the robust control to have predetermined constraints of the manipulated variables and the controlled variables; c) obtaining present values of the manipulated variables and the process variables said process variables corresponding to measurement parameters of the process; d) calculating new values of the process variables for a predetermined number of points in the future in order to have the values of the process variables within the predetermined range to obtain an optimal robustness of the resultant controller, the manipulated variables being within predetermined constraints, and the process variables falling within a predetermined range when controllable; otherwise, keeping process variable constraint violations to a minimum; e) from a plurality of solutions, selecting a most robust solution; and f) controlling the process in accordance with the most robust solution.