Numerical and Experimental Investigation of the Active Control by Using Electromagnetic Actuator

The possibility of controlling a flexible beam by using ElectroMagnetic Actuator (EMA) is assessed numerically and experimentally. The EMA has the advantage to be without contact with the structure so it could be applied on light and small mechanism. Nevertheless, the open-loop instability and the nonlinear dynamic behavior with respect to the excitation frequency could limit its application field. The EMA is designed and dimensioned in function with the experimental structure to be controlled. An inverse model of the EMA is proposed in order to implement a linear action block for the used frequency range. The control strategy is a fuzzy controller having displacements and velocities as inputs. A fuzzy controller of Takagi-Sugeno type is used. The air gap is estimated by using a modal approximation of the displacements issued from all measurements. A model of the studied system was necessary to calculate the modal shape. The characteristics of the model are identified experimentally. Several configurations of control are assessed by using numerical simulations. The block diagram used for numerical simulations is implemented under Dspace® environment. The implemented controller was tested experimentally in the context of impact perturbations. The results obtained show the effectiveness and the robustness of the implemented control.