Design methods of output proportional-plus-integral feedback controllers are studied for linear time invariant systems.
For single input single output (SISO) systems, a simple tuning method for designing proportional plus integral controllers is suggested. Assignment of a pair of dominant complex poles to overall transfer function is accomplished by combining conventional design specifications given in frequency domain and a performance index in time domain.
For general multi-input multi-output (MIMO) systems, necessary conditions for finding an optimal output proportional feedback gains are derived. In this case, quadratic performance index is used. The results are extended to proportional plus integral output feedback control. For illustrations, examples are solved and discussed.
Further studies on the delayed output feedback control and dynamic controller design are suggested.