WinPIM-CL Under Windows
Plant Model Identification in Closed Loop Operation PURPOSE Identification of parametric models for plants operating in closed loop is a necessity in practice in the following situations: - the characteristics of the plant do not allow an open loop identification (ex: plant with integrator behavior, unstable plant, important drift) - a controller exists already (ex: PID) - re-tuning of the controller in order: . to improve the performances of the closed loop . to assure the maintenance of the control system. A major advantage of the identification in closed loop is the fact that it provides in general a more suitable "control model" for the design of the controller. WinPIM-CL is an add-on to the WinPIM identification software. GENERAL DESCRIPTION WinPIM-CL uses the prediction error between the output of the closed loop system and the predicted output generated by predictor of the closed loop featuring explicitely an adjustable model of the plant.
CLOSED LOOP IDENTIFICATION TECHNIQUES WinPIM-CL determines the best plant model which minimizises the closed loop prediction error between the true output of the closed loop system and the predicted one. 3 main classes of identification algorithms are provided: - closed loop output error identification methods (CLOE algorithms) - filtered open loop identification methods (FOL algorithms) - instrumental variable methods (indirect algorithms). This method does not require the knowledge of the controller. VALIDATION OF THE IDENTIFIED MODELS The objective of the validation is to decide which identified model gives the best prediction of the closed loop system behavior (for a certain controller). 3 validation techniques are provided: - statistical tests on the prediction error - proximity analysis . the achiewed poles are obtained by identification of the closed loop . the computed poles are obtained using the identified model and the controller - time domain validation . comparison of real and simulated data DISTRIBUTION KIT - Floppy disk containing programs, help files and example data files - User's manual (operating instructions, theory, examples) MINIMAL HARDWARE/SOFTWARE CONFIGURATION - PC type 386 (or: 486, Pentium) under Windows 3.1 or Windows 95 with 1 Mo RAM (recommended: 2 Mo) - WinPIM software (Adaptech).