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 com- parison clearly demonstrated the advantage of the nonlinear SMC methods in meeting system performance characteristics, given system uncertainty and disturbances.