Problem 2 -- Saturation of signal u
In Section 3.1 of Astrom and Murray it states that the control input is limited to the range 0 <= u <= 1. You should include this in your model to ensure that the input never goes outside this range. This can be implemented in Simulink with the saturation block.
--Mary Dunlop 18:24, 6 October 2006 (PDT)