H" ROBUST CONTROL SYNTHESIS FOR A FIGHTER PERFORMING A COORDINATED BANK TURN

H" synthesis techniques are used to design a bank angle autopilot which commands a coordinated ba.nk turn. Two vari- ations of the H" design are compared to a multivariable classical design. Both of the H" designs have better performance and actuator robustness measures. The first H" design, however, contains an undesirable cancellation of a lightly damped Dutch roll mode, which causes a poor parameter robustness measure. The second H" design corrects this problem by using the same inner loop yaw damper as used by the classical design.