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2017
Conference Paper
Titel
Optimal placement of six inertial mass actuators for MIMO active vibration control on a laboratory truss structure
Abstract
Large flexible structures require a system comprising multiple actuators and sensors in order to efficiently control multiple structural modes. Controllability and observability are important properties to take into account when designing such a multiple-input multiple-output (MIMO) active vibration control (AVC) system. The actuator placement may influence the control performance, stability and energy efficiency of the control system. The actuators need to efficiently excite the dominant structural modes in order to achieve the desired control performance and minimize the effort. This work presents a practical analysis for the placement of six inertial mass actuators (IMAs) on a laboratory truss structure. A reduced order state space model of the truss structure is derived from a finite element (FE) model. Fourteen possible actuator mounting locations are considered. First, the problem of choosing the optimal placement for a single actuator is investigated and discussed. The problem is then extended to a system with six actuators. Possible optimal actuator placements are derived for the control of the dominant structural modes in a defined frequency range. A decentralized MIMO velocity feedback control with six IMAs is applied to the truss structure in order to assess the control performance, stability and power consumption. For simplicity, it is assumed that all IMAs have identical electro-mechanical characteristics. The control stability is discussed based on the analysis of the systems open-loop frequency response functions (OL-FRFs) using the generalized Nyquist criterion. The active control performance and the electrical power consumption of the control system for selected actuator arrangements is evaluated and compared. It is found that an optimal actuator arrangement can be identified using a performance index (PI). Arrangements with high PI guarantee good control performance and relatively lower power consumption.
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