Theoretical methods and practical aspects in continuous time system identification

This paper presents a procedure for time variant nonlinear system identification based on some experimental studies. Some of the system parameters change in time according to unknown laws. These laws are expressed as finite degree time polynomials whose parameters are included in the set of parameters to be identified. Mainly it is an extension of the procedure developed in [1]. The hierarchical structure identification method for rational expressions, proposed in [1], is now extended to time variant systems. The theoretical methods are now applied on some concrete platform. A sound knowledge of the system characteristics is of primary importance in any industrial application. Control selection and design procedures require the availability of detailed information about the components of the plant, with its linear and nonlinear, static and dynamic characteristics. Our paper presents the concretization of some experimental identification methods on experimental workbench from Quanser. HVAC installation is a test installation for controlling temperature in a chamber, and for parameters identification.