Design of optimal observers for structural control

An easy and fast approach based on the pole assignment method is given in order to design the optimal observer for high-order structural systems. It is shown that the optimal observer is not only the one which is characterised by an optimal gain; the optimal locations of the sensors and their types, the optimal locations of the control forces and their optimal design are also important factors in the design of the optimal observer used to control flexible structures. It has been found that the suitable sensor type and its location differ from one structure to another, depending on the natural frequencies and mode shapes of the structure. Two numerical examples are given to illustrate the application of this method.