Optimal actuator and sensor placement with regard to coupled electro-mechanical behaviour of smart structures

In this paper the problem of optimal actuator and sensor placement for active large flexible structures is considered. The proposed placement optimization method is based on balanced reduced models. It overcomes disadvantages arising from demanding numeric procedures related with high order structural models. Optimization procedure relies on H2 and H∞ norms, as well as on controllability and observability Gramians, related with structural eigenmodes of interest. The optimization procedure is documented by examples, which show a good agreement between the results obtained using different placement indices

Numerical modelling of coupled electro-mechanical problems for the state space controller design

Model development for coupled electro-mechanical problems in light-weight smart structure design is the subject of this paper. The paper addresses development of reliable models for the controller design of piezoelectric smart structures and systems, within an overall design procedure. Model development is based on the finite element (FE) approach, with application of modal reduction techniques for obtaining the state space models convenient for the controller design. Modal truncation and balanced modal reduction are considered as modal reduction techniques, with regard to controllability and observability issues. From the model optimization and verification point of view the experimental modal analysis and identification issues are addressed as well. Examples of model application to controller design document the feasibility of the technique

Optimal actuator and sensor placement with regard to coupled electro-mechanical behaviour of smart structures

In this paper the problem of optimal actuator and sensor placement for active large flexible structures is considered. The proposed placement optimization method is based on balanced reduced models. It overcomes disadvantages arising from demanding numeric procedures related with high order structural models. Optimization procedure relies on H2 and H∞ norms, as well as on controllability and observability Gramians, related with structural eigenmodes of interest. The optimization procedure is documented by examples, which show a good agreement between the results obtained using different placement indices

Identification of modal parameters for complex structures by experimental modal analysis approach

In this research, we have proposed a methodology for experimental identification of modal parameters based on measurement of the frequency responses of structures with complex geometries and performed an overall investigation of structural behavior on a funnel-shaped inlet of magnetic resonance tomograph. Several identification methods are implemented and compared: complex exponential, least-squares complex exponential, and polyreference least-squares complex exponential. We have implemented the modal parameter identification methodology within our own graphical user interface supported by MATLAB to create an independent tool for modal analysis. The estimation methods are compared and the comparison results are summarized showing based on tabular representation and stabilization diagrams significant advantage of the proposed methodology for determining eigenfrequencies, damping coefficients, mode shapes, and residues for complex structures investigated in broad band of frequencies. Runtime for the execution of algorithms vary depending on the applied method, assumed order of the model used for estimation, and the number of measurements, that is, inputs and outputs

Identification of parameters in nonlinear geotechnical models using extenden Kalman filter

Direct measurement of relevant system parameters often represents a problem due to different limitations. In geomechanics, measurement of geotechnical material constants which constitute a material model is usually a very diffcult task even with modern test equipment. Back-analysis has proved to be a more effcient and more economic method for identifying material constants because it needs measurement data such as settlements, pore pressures, etc., which are directly measurable, as inputs. Among many model parameter identification methods, the Kalman filter method has been applied very effectively in recent years. In this paper, the extended Kalman filter – local iteration procedure incorporated with finite element analysis (FEA) software has been implemented. In order to prove the effciency of the method, parameter identification has been performed for a nonlinear geotechnical model

Identification of modal parameters for complex structures by experimental modal analysis approach

In this research, we have proposed a methodology for experimental identification of modal parameters based on measurement of the frequency responses of structures with complex geometries and performed an overall investigation of structural behavior on a funnel-shaped inlet of magnetic resonance tomograph. Several identification methods are implemented and compared: complex exponential, least-squares complex exponential, and polyreference least-squares complex exponential. We have implemented the modal parameter identification methodology within our own graphical user interface supported by MATLAB to create an independent tool for modal analysis. The estimation methods are compared and the comparison results are summarized showing based on tabular representation and stabilization diagrams significant advantage of the proposed methodology for determining eigenfrequencies, damping coefficients, mode shapes, and residues for complex structures investigated in broad band of frequencies. Runtime for the execution of algorithms vary depending on the applied method, assumed order of the model used for estimation, and the number of measurements, that is, inputs and outputs

Identification of modal parameters for complex structures by experimental modal analysis approach

In this research, we have proposed a methodology for experimental identification of modal parameters based on measurement of the frequency responses of structures with complex geometries and performed an overall investigation of structural behavior on a funnel-shaped inlet of magnetic resonance tomograph. Several identification methods are implemented and compared: complex exponential, least-squares complex exponential, and polyreference least-squares complex exponential. We have implemented the modal parameter identification methodology within our own graphical user interface supported by MATLAB to create an independent tool for modal analysis. The estimation methods are compared and the comparison results are summarized showing based on tabular representation and stabilization diagrams significant advantage of the proposed methodology for determining eigenfrequencies, damping coefficients, mode shapes, and residues for complex structures investigated in broad band of frequencies. Runtime for the execution of algorithms vary depending on the applied method, assumed order of the model used for estimation, and the number of measurements, that is, inputs and outputs