The effects of disturbance-modeling errors on performance of disturbance accommodating control (DAC) systems

This thesis analyzes, and develops a methodology to predict, performance degradation of disturbance-modeling errors for systems designed with a Complete Disturbance Cancellation (CDC) type DAC controller when an unfamiliar disturbance impacts the system. Through simulation, the effects of disturbance-modeling errors on some particular example closed-loop systems designed with a DAC/CDC controller against various basic unfamiliar disturbance waveforms are shown to cause performance degradation on the output y(t) of the system. A methodology is then developed to analytically predict these steady-state performance degradations via an error function utilizing the disturbance transfer-function G 0(s) and the difference between the basis-functions in the "design" basis-set and the basis-functions of the "actual" disturbance.