  Optical sensors are often mounted on moving platforms to aid in a variety of
tasks like data collection, surveillance and navigation. This necessitates the
precise control of the inertial orientation of the optical sensor line-of-sight
(LOS) towards a desired stationary or mobile target. A two-axes gimbal assembly
is considered to achieve this control objective which can be decomposed into
two parts - stabilization and tracking. A novel state space model is proposed
based on the dynamics of a two-axes gimbal system. Using a suitable change of
variables, this state space model is transformed into an LTI system. Feedback
linearization based control laws are proposed that achieve the desired
objectives of stabilization and tracking. The effectiveness of these control
laws are demonstrated via simulation in MATLAB based on a typical model of a
two-axes gimbal system.
