An optimal sensor/actuator placement method for flexible structures considering spatially varying disturbances

Disturbances acting on flexible structures at spatially varying locations instead of fixed points may lead to deteriorated vibration control performance. To tackle this problem, this article presents an optimal sensor/actuator placement method, in which the closed-loop spatial Script capital H-2 norm is employed as the optimization criterion. In addition, a new way to calculate the spatial Script capital H-2 norm is proposed, which is independent of the modal orthogonality assumption in previous research. An optimization framework is established to optimize sensor/actuator placement by minimizing the closed-loop spatial Script capital H-2 norm using the genetic algorithm. Comprehensive numerical simulations are implemented on a fixed-fixed plate to validate the proposed method. Results show that magnitude of vibrations is reduced and decays faster after the optimization, which indicates that the proposed method markedly improves control performance when spatially varying disturbances exist.