Application of Structured Singular Value Synthesis to a Fighter Aircraft

The results of a design study to examine the control of a fighter aircraft at high angles of attack are presented. The flight condition considered represents an extreme point along a demanding large angle maneuver. Control laws are developed for a linear model of the aircraft using structure singular value synthesis to take the parameter uncertainty structure into account. The control objective is to attain acceptable flying qualities despite variations and uncertainty in the aircraft´s aerodynamic coefficients. Desired flying qualities are embedded in ideal models of the angle of attack, sideslip angle, and stability axis roll rate responses to pilot inputs. The control objective is met by minimizing the weighted error between the ideal model outputs and the plant outputs while including structured parameter uncertainty in the design model.