A new guidance law of bank-to-turn(BTT) missiles based on the singular perturbation technique is presented in this thesis. In this new guidance law, the lateral control commands are total acceleration and roll angle.
The guidance law of existing BTT missiles is an ad-hoc method derived from the skid-to-turn(STT) guidance law. However, the pitch and yaw dynamics of BTT missiles are coupled in a nonlinear fashion so that the existing guidance law is not optimal. Recently, some optimal guidance laws for BTT missiles were derived by using the singular perturbation technique but they are limited for the cases when the lateral control command is roll rate.
In this thesis, the controllability for the linearized system is checked by classical linear control theory. It is revealed that the system becomes uncontollable when the nominal acceleration command approaches to zero. This problem is avoided by employing the biased guidance law in which the acceleration command has a constant bias. The approximate solution for this guidance is then obtained by using the singular perturbation technique.
The new guidance algorithm is incorporated in a computer simulation, and examined numerically. The proposed guidance algorithm is also compared with an existing BTT guidance algorithm based on proportional navigation.
