Seeker head line-of-sight sliding mode control

Low cost seeker head line-of-sight control design presents a great challenge due to system uncertainty and internal disturbances, e.g. friction, caused by the simple system components. Using conventional control methods like proportional-derivative or proportional-integral-derivative (PID) cannot satisfactorily meet the performance characteristics in the whole seeker field-of-regard. Nonlinear control methods, such Sliding-Mode Control (SMC), may introduce enhanced capabilities to deal with system uncertainties and disturbances. In this paper, a comparison between the conventional PID and SMC design methods is addressed. The resulting controllers are compared using numerical simulation and laboratory tests. The comparison clearly demonstrated the advantage of the nonlinear SMC methods in meeting system performance characteristics, given system uncertainty and disturbances.