A new type of linear magnetostrictive motor

Magnetostrictive materials that may alter their shape significantly in response to external magnetic fields are used in unidirectional motion and force actuators and linear motors. In this study, we present a linear magnetostrictive motor (LMM) powered through a pulse width modulation (PWM) drive, whose core is a waveform controller of DRV101T type. Mathematical modeling and numerical simulations (in the finite element method) are used in the design phase to optimally size the LMM and to predict its behavior in stationary and dynamic working conditions, for a duty cycle (percentage of time when the driving coil is active) % and the frequency kHz. The mechanical bias, provided by a spring system, is complemented with a bias coil, which is powered by a PWM stage too. This solution provides for enhanced and flexible control, while reducing the Joule losses to a minimum. LMM actuation is also provided through a second coil. The frequency of the voltage applied to the actuation coil is the same with the frequency of voltage applied to the bias coil. The concept of the LMM drive and its construction are validated through interferometry, vibration and thermal imager measurements.