ADAPTIVE FILTERS FOR REAL-TIME SYSTEM-IDENTIFICATION AND CONTROL

An adaptive filter or a neural network concept has been used to develo p an algorithm for real-time system identification and control. The al gorithm permits not only identification of transfer functions of linea r structural systems but also extraction of modal parameters such as n atural frequencies, damping ratios, and mode shape coefficients in rea l time. Because the algorithm is capable of identifying a single mode at a time, bandpass filters are employed to make it work properly for systems with multiple modes. The algorithm has been implemented in a d igital signal processor-based data acquisition and control system for the system identification and control experiments with the U.S. Naval Research Laboratory space truss. It was experimentally demonstrated th at the algorithm was capable of identifying modal parameters of the tr uss accurately by using a truss tip-mounted accelerometer as a sensor and a piezoceramic active strut as a disturbance source. The algorithm was also successfully employed to conduct active vibration suppressio n and performance monitoring of the feedback controller by using the a ctive strut and a collocated force transducer.