Version 1
: Received: 12 February 2024 / Approved: 12 February 2024 / Online: 12 February 2024 (14:17:37 CET)
Version 2
: Received: 12 February 2024 / Approved: 13 February 2024 / Online: 13 February 2024 (11:46:49 CET)
Durante, F.; Raparelli, T.; Beomonte Zobel, P. Resistance Feedback of a Ni-Ti Alloy Actuator at Room Temperature in Still Air. Micromachines2024, 15, 545.
Durante, F.; Raparelli, T.; Beomonte Zobel, P. Resistance Feedback of a Ni-Ti Alloy Actuator at Room Temperature in Still Air. Micromachines 2024, 15, 545.
Durante, F.; Raparelli, T.; Beomonte Zobel, P. Resistance Feedback of a Ni-Ti Alloy Actuator at Room Temperature in Still Air. Micromachines2024, 15, 545.
Durante, F.; Raparelli, T.; Beomonte Zobel, P. Resistance Feedback of a Ni-Ti Alloy Actuator at Room Temperature in Still Air. Micromachines 2024, 15, 545.
Abstract
This paper illustrates an experimental activity for the closed-loop position control of an actuator made using shape memory alloy (SMA) wire. A solution with the self-sensing effect was implemented to miniaturize the systems, i.e., without external sensors. A proportional control algorithm was initially used, demonstrating the idea's feasibility: the wire can behave simultaneously as an actuator and sensor. An experimental investigation was subsequently conducted for the optimization of the developed actuator. As for the material, a Flexinol wire, Ni-Ti alloy, with a diameter of 0.150 mm and a length of 200 mm, was used. Preliminarily, a characterization of the SMA wire at constant and variable loads was carried out: the characteristics detected are elongation vs. electric current and elongation vs. electrical resistance. The control system is PC-based with a data acquisition card (DAQ). A drive board has been designed and built to read the wire's electrical resistance and power it by pulse width modulation (PWM). A notable result is that the actuator works with good precision and in dynamic conditions, even when it is called to support a load up to 65% different from that for which the electrical resistance-length correlation has previously been experimentally obtained, on which the control is based. This opens up the possibility of using the actuator in a counteracting configuration with a spring, which makes hardware implementation and control management simple.
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
