A control system has a detector for obtaining a detected signal corresponding to a controlled variable of a controlled system and a controller for supplying the controlled system with a control signal corresponding to the detected signal. The controller includes an error circuit for producing an error...http://www.google.es/patents/US4821168?utm_source=gb-gplus-sharePatente US4821168 - Control system with improved robustness to disturbances
Control system with improved robustness to disturbances
