Saturation protection for feedback linearizable systems using sliding mode theory

It is shown that sliding mode control is equivalent to feedback linearization with an appropriate choice of desired output dynamics. It is this equivalence that leads to the development of a control command limiting algorithm that provides actuator saturation protection for input/output feedback linearizable systems with more inputs than outputs. The command limiting algorithm is integrated with an optimal control redundancy algorithm to form a complete control allocation method. The control allocation minimizes control effector deflections for control redundant situations and limits control commands for control deficient situations. The control allocation method is applied to a tailless fighter aircraft model.