On the stability of adaptive pole-placement controllers with a saturating actuator

This paper addresses the following question: How do existing pole-placement algorithms work in the case of a saturating input? The stability of such algorithms and the modifications needed to make them work in the presence of saturation are examined here. The net results of this examination are: a mathematical condition for closed-loop stability, physical intuition behind this condition, some explanation of why adaptive control has been successfully implemented - even while ignoring saturation, and some design rules for doing adaptive control on linear plants with saturating actuators.