Strategies for Distributed Piezoelectric Actuator / Sensor Placement by Noise Effect Minimisation and Modal Controllability / Observability

This paper investigates the problem of placement procedure for distributed piezoelectric actuators and sensors. Two placement techniques are proposed. The first one is based on the controllability and observability Grammians of the system expressed in a modal state-space coordinates. The controllability Grammian is then able to quantify how structural modes are controllable with a set of predefined actuators, while the observability Grammian expresses how much structural modes can be observed from a set of predefined sensors. The second placement technique is based on the selection of the best sensor sets which, for each selected structural modes, have the best signal to noise ratio. The sensor selection is performed by inspecting the Fisher information matrix. The number of sensors is then reduced, in an iterative manner, by eliminating locations that do not contribute significantly to the linear independence of the target modal partitions.