SUMMARY
This presentation describes a new design for a magnetostrictive actuator that employs individually controlled coils distributed axially along the magnetostrictive rod. The multi-coil actuator can operate effectively at frequencies as high as 10,000 Hz with 900 N force and 50 microns of displacement. Conventional, single coil actuators with the same parameters for force and displacement develop significant attenuation in their response at frequencies above the first longitudinal vibration resonance at about 2750 Hz. This presentation shows a new mathematical model of the actuator that represents the spatial distributions of magnetic field and vibration, devises a control design that takes advantage of the multiple inputs to control the displacement of the actuator while consuming a minimum of electrical power, and describes a prototype multi-coil actuator and experimental system developed to test the idea. The simulations of the multi-coil actuator and control design demonstrate successful transient operation of the actuator over the targeted frequency range with feasible levels of power and current supplied to the actuator. Experimental tests of the design are able to verify modeling of the actuator and reproduce the simulated control performance within the constraints of the experimental system.