Development of a cascade position control system for an SMA-actuated rotary actuator with improved experimental tracking results

Abstract

Hysteresis and significant nonlinearities in the stress-strain-temperature characteristics of shape memory alloy (SMA) actuators prevent effective utilization of these actuators and make them difficult to control. Due to these effects, the position control of SMA actuators has been a great challenge for many industrial applications. In this study, a cascade control for position tracking using torque and position measurement of an SMA-actuated rotary actuator is considered. The effects of the SMA characteristic model on control performance are also focused when simulation consequences are directly applied in practice. Based on nonlinear and unknown dynamics of an SMA actuator, a torque regulation adaptive controller using modified Brinson model is developed that requires to approximate the parameters of the system by only measuring SMA force and actuator rotation. Although it is shown that only an approximate model of the system is sufficient to develop the proposed controller, the system dynamic is simulated using MATLAB software, and the characteristics of SMA wire is considered by both modified Brinson constitutive model and Liang and Rogers constitutive model. The controller gains are regulated for both of the mentioned models using simulation. Finally, the performance of both controllers is further evaluated experimentally, and the accuracy of the proposed controller based on the modified Brinson model is compared to the controller based on the Liang and Rogers model. It is shown that since the Brinson model has a better prediction of the SMA wire behavior, the simulation results based on the modified Brinson model have better conformity to reality.

A Review of SMA-Based Actuators for Bidirectional Rotational Motion: Application to Origami Robots

“…The prototype was able to provide around 100°rotation with an error smaller than 0.5°. The model was applied in works of (De Sars et al, 2010;Ruth et al, 2015;Moghadam et al, 2019) and the results showed that the combination of constitutive model and SMC offers an improvement of actuator's control accuracy of angle than the classic PID controller (Moghadam et al, 2019). One needs to remind that these models were applied to normal-motion-driven SMAs.…”

“…Such investigation is presented in Velázquez et al (2006), in which he developed a temperature and deformation-based function of electrical resistance, resulting in improvement of modeling precision. The influence of latent heat is another factor that has been usually neglected for mathematical simplicity (Moallem and Tabrizi, 2008;Peraza-Hernandez et al, 2014;Guo et al, 2015;Liu et al, 2019;Moghadam et al, 2019). Besides the utilization of the reduced-order model, the numerical approach using 3D FEM method are presented in the literature in order to study the temperature evolution more accurately (Abadie et al, 2009;Firouzeh and Paik, 2015).…”

“…1D quasistatic phenomenological models implemented in numerical software are frequently utilized to predict the thermomechanical response of actuators. The LRM/MB are demonstrated as a suitable model for prediction of the quasistatic and dynamic response of passive or active biased normal stress actuator for BRM (Gilardi et al, 2010;Doroudchi et al, 2018;Liu et al, 2019;Moghadam et al, 2019). Moallem and Tabrizi (2008) introduced the rate of martensite factor evolution based on LRM for dynamic response prediction.…”

“…Moallem and Tabrizi (2008) introduced the rate of martensite factor evolution based on LRM for dynamic response prediction. Based on this approach, Moghadam et al (2019) shown an improvement of precision of controlling using a modified version of MB. Additionally, the LRM model is validated experimentally using antagonistic SMA torsional spring in (Sheng et al, 2017).…”

Multi-field coupled dynamics for a movable tooth drive system integrated with shape memory alloys

“…Takeda studied a reciprocating rotary actuator of SMA tapes in which according to the torsional deformation characteristics of SMA tapes, a graphical design method of the actuator was proposed [ 16 ]. Moghadam investigated a position tracking control method of SMA driven rotating actuator using torque and position measurement, and evaluated the performance and accuracy of the controller by experiments [ 17 ]. Moghadam proposed a fast response control method of SMA driven rotating actuator based on robust sliding mode control, which uses both SMA strain and temperature as feedback signals [ 18 ].…”