ABSTRACT
The proposed design provides generalized Internal Model Control (IMC) filters that can be used to obtain good results in terms of output sensitivity, or in terms of input sensitivity. The objective of a control system is to make the output y behave in a desired way by manipulating the plant input u. Historically, the inherent shortcomings of the IMC method have resulted in the search of new filters and/or alternative procedures: for minimum-phase unstable plants, Campi suggested a filter which allows easy adjustment of the closed-loop bandwidth as well as a robustness improvement. In any practical design method, robust performance is the ultimate goal: the people want the controller to work well under uncertain circumstances. However, the performance for load disturbances is poor, showing a sluggish return to steady state.
