Performance Evaluation of a MIMO Control System with Limited Actuators

Performance degradation of multivariable control systems having limited actuators is often handled by augmenting the controller with integral windup protection, which attempts to maintain system performance when limits are encountered. This work describes a method to analyse such systems to determine precisely what stability and performance degradation is incurred under limited conditions. It is shown that by reformlating limited actuator commands as resulting from multiplicative perturbations to the corresponding controller requests, linear system evaluation tools can be utilined to obtain quantitative measures of stability and performance degradation.