Experimental evaluation of a shape memory alloy wire actuator with a modulated adaptive controller for position control

Abstract

This paper presents an experimental investigation of position control of a shape memory alloy (SMA) wire actuator with adaptive and modulated adaptive controllers. The transfer function model of the SMA wire actuator is determined from the experimental open loop response. Adaptive controllers, namely LMS–GSPI, RLS–GSPI and Kalman–GSPI, and modulated adaptive controllers using pulse width modulation (PWM) are designed. The performances of these controllers are experimentally investigated for the position control of an SMA wire actuator with and without thermal disturbance. Experimental results demonstrate that the modulated adaptive controllers outperform adaptive controllers.

Modulated adaptive fuzzy controller for position control of SMA wire actuator

“…The experimental setup reported in [3] is used to conduct the open and closed loop performance in this work. The schematic of the experimental setup used to measure and control the SMA actuator is shown in Fig.…”

“…However, the control of SMA position or displacement is difficult due to its inherent properties such as nonlinearity, hysteresis. Different controllers have been developed to control the SMA actuator with position or displacement feedback and demonstrated a potential for SMA actuators to be used as motion control actuator [2][3][4][5]. The non-linearity and hysteresis of SMA actuator posed difficulties in expressing these behaviors in modeling the SMA actuator.…”

Pulse width modulation–based temperature tracking for feedback control of a shape memory alloy actuator

“…The shape of the SMA actuator changes during phase transformation and a fixed cylindrical geometry assumption cannot be used as in straight SMA wires. Bhattacharyya et al (2002) and Senthilkumar et al (2012) showed that temperature-current relation of SMA can be represented with an empirical relation: $$Tfalse(tfalse)=T_{\infty }+\frac{a_1}{a_2}IRfalse(1-e^{-a_{2}t}false)$$ where I is the current supplied to the SMA, R is the electrical resistance of the SMA, a 1 and a 2 are the parameters to be determined through experiments. The resistance change of the SMA actuator during phase transformation is less than 0.1 Ω and it is assumed to be constant.…”

Investigation of Shape Memory Alloy Spring Elastic Coefficient Based on Varying Applied Currents in a Cardiac Assist Device

“…This effect means that the material can recover to its original shape and undergo a transformation from parent or austenite phase to martensite phase. [37][38][39] Figure 1 presents the schematic of phase transition of the SMA dominated by heat and stress together. In 1981, Miyazaki et al found that the stress-strain curves of Ni-Ti alloys were significantly different based on different temperatures.…”