Inertial platform synthesis employing observers to accommodate disturbances and coupling

The design of a multivariable control system is treated. Observer theory is utilized in the design and disturbance inputs are accounted for. The observer is only required to reconstruct the states of the plant associated with the "slow" modes of the system. The parameter insensitivity (gain margin) needed is obtained in this way. The observer parameters are selected so as to maximize gain margin and to minimize disturbance transmittances. The errors introduced in neglecting the "fast" modes are also taken into account.