Multivariable Control of a 3 Fin Torpedo

Current high performance torpedos are controlled by 4 surfaces arranged in orthogonal pairs ie: vertical rudders and horizontal elevators. Reducing the number of control surfaces from 4 to 3 will result in cost savings but induces dynamic cross-coupling, primarily between yaw and roll channels. In this paper the axial cross coupling is examined, decoupling pre-compensators designed using multivariable system theory and comparison made between the performance of autopilots designed with and without decoupling applied.