APPLICATION OF REAL MIXED MU-COMPUTATIONAL TECHNIQUES TO AN H(INFINITY) MISSILE AUTOPILOT/

A multivariable missile autopilot is synthesized using an H-infinity a pproach. A tradeoff is achieved between performance, actuators solicit ation and uncertainties in the actuators and bending modes dynamics. R obust stability and performance of the control law are then studied in the face of large real parametric aerodynamic uncertainties: computat ional techniques for real and mixed Cc analysis (namely De Gaston and Safonov's, Dailey's, Jones', Young and Doyle's, Fan, Tits and Doyle's and Safonov and Lee's methods) are briefly reviewed before being used to compute either the exact value, or an interval of the structured si ngular value (SSV). For small amounts of parameters, the upper and low er bounds provided by these methods are compared to the exact value, c omputed by De Gaston and Safonov's method. For larger amounts of param eters, NP hardness of the problem prohibits the use of algorithms whic h compute the exact value: these algorithms are indeed necessarily exp onential-time. As an alternative in this case, the use of polynomial-t ime methods for computing upper and lower bounds leads in our examples to accurate approximates of the real and mixed structured singular va lues.