Multivariable controller design with integrity

In this paper, a new approach to multivariable controller design with integrity is introduced. This method is based on the reinterpretation of individual transmission channel representation of MIMO systems defined in the individual channel design (ICD) method. It provides a procedure for finding stabilizing PID controllers for two input - two output (TITO) systems which maintain stability of the multivariable system even when one of the controllers fails to operate. The PID controllers are directly designed for the unknown systems from frequency response data, without developing mathematical models and without system identification. A key ingredient for the success of the method is that complete sets of stabilizing controllers can be found since such sets have to be intersected. It is shown that strategic processing of a few measurements can achieve this goal.