2025/11/01 by Shuangqing Yu, Shuangqing YU, Jinguo Liu +3
Materials Science · Engineering · #Shape Memory Alloy Transformations #Aeroelasticity and Vibration Control #Prosthetics and Rehabilitation Robotics
paper · doi:10.1088/1361-665x/ae1bec
Abstract Lightweight and compact deployable structures are essential for manufacturing large spacecraft, enabling human exploration of deep space. Deployable mechanisms utilizing shape memory alloy (SMA) actuators meet these structural requirements without adding extra weight. However, the hysteresis, nonlinearity, and time-varying properties of SMA present challenges for their application. This study focuses on designing and validating a controller that combines an Extended State Observer (ESO) with Sliding Mode Control (SMC) to achieve accurate position control of SMA actuators. A mechanistic model of the SMA actuator was established, and the ESO was designed to monitor and compensate for uncertainties arising from parameter fluctuations and modeling inaccuracies. An experimental setup was established to measure the SMA material parameters for identification and validation. Numerical simulations were conducted to compare the proposed control method with a traditional SMC, evaluating the dynamic behavior and response of the SMA actuators under various target displacement inputs. The findings revealed that the proposed controller achieved faster convergence times and lower Root Mean Square Error values of 0.29398 and 0.06842, representing improvements of 34.96% and 19.71% over the traditional SMC controller. Thus, this ESO based controller demonstrates rapid responsiveness, high precision, and robustness, with successful applications in driving deployable structures, highlighting its practical value.