Modeling and optimization of magnetic actuators to vibration control

Rafael Pilotto¹; Ricardo Ugliara Mendes¹; Katia Lucchesi Cavalca¹

¹ UNICAMP

doi:10.20906/CPS/COB-2015-0167

Resumo

The use of magnetic actuators for vibration reduction aims to substitute, in some occasions, the magnetic bearings, since the magnetic actuator involves less complex project requirements in its configuration. The present study consists of evaluating how a magnetic actuator behaves while controlling vibration in a flexible metallic beam, modeled using the finite elements method. Due to design restrictions involving considerable flexibility of a thin beam, there are limitations in the positioning of the actuator in the beam optimal position (highest amplitude of vibration). Hence, the magnetic actuator is inserted into the model utilizing electromagnetic theory. Other components are added to the model through the theory of control of mechanical systems, such as: current amplifier, inductive position sensor and a PID controller (Proportional-Integral-Derivative). The actuator and the sensor are placed in different nodes in the computational model, in order to study the effectiveness of the actuator-controller-sensor system depending on its positioning in the beam. The parameters of the PID controller for the entire length of the beam were obtained using the Ziegler-Nichols optimization method for the locations of the beam where the actuator-sensor system was positioned and a LPV (Linear Parameter Varying) technique was applied to the deployment of these parameters as a function of the beam length. For the experimental validation, two devices were used to act as an external excitation in the beam: an electromechanical equipment called Shaker, which generated sinusoidal waves in the natural frequencies of the system, in order to verify the behavior of the actuator/controller in critical conditions, and a modal hammer that excited the beam through a single impulse, which allowed the energy dissipation to be measured as a function of the time period until the complete damping of the transient response. Thus, the behavior of the magnetic actuator in vibration control is evaluated regarding its position alongside the flex

Palavras-chave: Flexible beam; Vibration Control; Adaptative Control; PID; LPV