Use of test signals in system identification by quasilinearization

Identification of linear systems with unknown input gains and parameters by quasilinearization is studied both by the boundary value method and the performance index method. It is shown that the boundary value method requires a test signal whose order of complexity is proportional to the order of the system. On the other hand, with the performance index method, it is proved that the normal inputs to these systems are sufficient for complete system identification. This is significant because the most important consideration of system identification is to be able to identify the system under normal operation with as little disturbance to the system operation as possible.