A practical approach to selecting weighting functions for H∞ control and its application to a pilot plant

Methods of commissioning weighting functions to reflect system specifications in H_∞ design are investigated. For constrained control effort, such as position and rate limits of an actuator, an explicit weighting function expression is derived. A basic form for the performance weighting function is suggested, whose physical connections with system steady-state performance and transient response performance are clearly explained. A novel method for the selection of weighting functions in H_∞ mixed sensitivity design is proposed to directly control the percentage overshoot. Finally, the proposed methods are demonstrated by the roll-angle control design of a laboratory-scale model of a vertical take-off aircraft.