Roll loop design for bank-to-turn guidance by polynomial methods

Computer programs, based on the polynomial approach, have been used to design fixed, linear, optimal roll loop controllers using typical plant and disturbance models. Design parameters may be adjusted to produce systems which satisfy a hard limit on aileron angle and which have a range of step responses. The controller complexity may be reduced as part of the design process. The performance of the resulting single-loop system is examined and compared with that of the corresponding double loop design in which roll rate as well as roll angle is fed back. In cases where weathercock oscillation is a problem, it is demonstrated how the system attenuation at the weathercock frequency might be increased.