Magnetostrictive Actuator Views

• General Goods

Giant magnetostrictive actuators are designed and fabricated with home-made TbDyFe magnetostrictive rods. The corresponding static and dynamic characteristics are tested. The total output displacement can be obtained up to 100 µm and the output force up to 1500 N. The dynamic responses of input and output are accordant and have a small hysteresis. Experiments on active vibration control are implemented in single-degree-of-freedom (DOF) and six-DOF platforms in a flexible space structure. The excellent damping effect, up to 30 dB, proves the good performance of the actuators, the feasibility of the control algorithms, and the reasonable design of the six-DOF platform.

The paper proposes a two-stage model able to describe the dynamic behavior of a commercial magnetostrictive actuator in the frequency range of interest for fast actuation purposes. The first stage is a static model of hysteresis, while the second one is a linear dynamic model. The model structure allows to define well-assessed identification procedures for both stages. In particular, the identification of the dynamic stage is realized by the compensation of the transducer's hysteresis, through the employment of a pseudo-compensator. Experimental validation of the model is also reported and further applications to other magnetostrictive actuators is addressed.