Optimal sensor placement for state estimation of a thin double-curved shell structure

Thin double-curved shell structures are often found in architecture and engineering when large areas are spanned without intermediate supports. Due to their large span and low weight,the influenceof external loads, like snow and wind,is significantand may lead to inefficienciesin the load bearing behavior as well as induce vibrations. Research has shown that such negative effects can be compensated by adding active comp onents to the structure,allowing aload- and oscillation-dependent response to improve structural stability. Aprincipal requirement of such systems is the determination of the current state through the impleme ntation of appropriate sensors.This paper presents amethod for optimal sensor placement on shell structures such that the state of oscillation of the system can be reconstructed and model-based methods for active vibration damping can be applied.The method uses the number of sensors as asur- rogate for implementatio ncost and an observability measure as optimization objectives.The latter is derived from the observability gramian and considers the average observation energy.The influenceof measure ment noise and model uncertainties on the observability of the system is taken into account explicitly. The method is tested on aflexiblethin shell structure that is modeled by Finite Element Meth- ods using ANSYS.The equations of motion are transformed into modal space where model reduction methods are applied.The resulting model is used to optimize the sensor location s.The optimi zation is performe dby the Multi-objective Simulated Annealing algorithm.The proposed concept is tested on an experimental plant and optimization results and exempl ary optimal sensor configurations are presented.