Input screening method for disturbance rejection

The control structure selected has a strong effect on the performance of a closed loop system with respect to its disturbance rejection capability. But the methods used for its selection usually result in a combinatorial problem. To overcome this difficulty, an input pre-screening criterion, the input-disturbance alignment (IDA) measure, is proposed. Some important features of the new indicator and its relationship with other well-known controllability measures are presented. The case study included shows that the IDA can be used for efficient selection of manipulated variables from a large number of candidate inputs. These then form the best control structure for disturbance rejection.