Improved LQG benchmark based control performance monitoring for multivariable systems

By subspace identification technique, this article investigates the problem of control variance performance monitoring for multivariable systems. Based on LQG benchmark, an improved strategy is developed to overcome the deficiency of the conventional LQG benchmark based methods in practical applications. The multivariable system is first decomposed into multiple multi-input single-output (MISO) subsystems. Then the LQG benchmark is respectively obtained for each subsystem and the corresponding variance performance assessment indicator is yielded. The performance monitoring result of the overall system can finally be derived by weighting to each subsystem's assessing indicator. Simulation example illustrated the validity of the proposed method.