Design rules for multivariable feedback systems

Considers a class of multivariable feedback design problems that often arises in applications. These consist of strongly interacting systems that have bandwidth limitations which in turn impose design trade-offs when a decentralized controller is implemented. Applications examples exist for which a multivariable controller yields improved performance. Since such a controller cannot remove the source of the limitations, it follows that performance improvement is obtained by using crosscoupling terms in the controller. The nature of the required crosscoupling term depends upon whether the bandwidth constraint arises from an actuator or a sensor deficiency