Mechatronic design and instrumentation of sensor-control unit for MSM-based actuator

This Master’s thesis focuses on the development and implementation of a sensor-control unit for an actuator based on Magnetic Shape Memory (MSM) alloys. These innovative materials combine the properties of traditional shape memory alloys with the rapid response of magnetic materials, enabling large deformations with extremely fast reaction times. However, the complexity of their nonlinear behavior, influenced by magneto-mechanical coupling and hysteresis phenomena, presents a significant challenge in modeling and control. The work is structured into three main phases. The initial section outlines the design and optimization of an experimental system that incorporates an MSM actuator, a laser sensor for displacement measurement, and a Speedgoat-based control unit used for real-time signal acquisition and processing. Specific considerations are given to the resolution of technical issues, such as sensor noise, and the optimization of the system’s operational range. Subsequently, the dynamic identification of the MSM actuator is carried out, with the system divided into a linear subsystem (represented by a mass-spring-damper model) and a nonlinear behavior represented by hysteresis. The latter is modeled using the Krasnosel’skii-Pokrovskii approach. The overall model is validated through experiments conducted in both time and frequency domains, which demonstrate a high degree of correspondence with the behavior of the actuator. In conclusion, the thesis presents the development of a combined control system comprising a classical feedback action (PI controller) and a novel feedforward action based on the hysteresis model. Through simulations and experimental tests, the proposed control system is demonstrated to enhance the precision of the MSM actuator’s performance. This work makes a contribution to the advancement of knowledge in the field of MSM-based actuators, demonstrating their potential for practical applications and proposing innovative solutions for their integration into advanced mechatronic systems.