Multi-input multi-output PI controller design

The design of MIMO PI controller is formulated as an LQR problem. The weighting matrices of the quadratic performance index are chosen so that tuning can be done for each input-output channel and for a trade-off between transient response and robustness with respect to modeling error. The number of tuning parameters is the same as that of a decentralized PI controller. A design example is given to demonstrate the feasibility of the proposed approach.