OPTIMAL FEEDBACK CONTROL OF SISO SATURATION SYSTEMS OVER A CLASS OF NONLINEAR STABILIZING CONTROLLERS

✍ Scribed by D. Sourlas; J. Choi; V. Manousiouthakis

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 407 KB
• Volume: 7
• Category: Article
• ISSN: 1049-8923
• DOI: 10.1002/(sici)1099-1239(199705)7:5<449::aid-rnc229>3.0.co;2-1

✦ Synopsis

This paper focuses on the feedback control of a linear single-input single-output process in the presence of input saturation constraints. First, closed-loop stability is guaranteed through the use of a parametrization of all nonlinear stabilizing controllers in terms of an S-stable parameter Q. Then, a performance measure is proposed that quantifies closed-loop performance with respect to a finite number of disturbances. Subsequently, the best achievable performance is quantified over a class of nonlinear stabilizing controllers parametrized in terms of absolutely summable second order Volterra operators. The resulting computational procedure involves the solution of a sequence of MILP's. An illustrative example is employed to demonstrate the proposed procedure. This example establishes that, for this performance measure, there may exist a value of the saturation bound for which the best achievable control system performance of the saturating system is strictly better than the corresponding best achievable linear performance. The same example also demonstrates that nonlinear control can perform strictly better than linear control for a performance measure that employs a finite number of disturbances.