A hybrid dynamic model of shape memory alloy spring actuators. (January 2018)

• Record Type: Journal Article
• Authors: Cortez-Vega, R.; Chairez, I.; Luviano-Juárez, A.; Feliu-Batlle, V.
• Is Part Of: Measurement. Volume 114(2018)
• Page Start: 340
• Page End: 353
• Publication Date: 2018-01
• Subjects: Shape Memory Alloy -- Smart actuator -- Hysteretic model -- Hybrid model; Weights and measures -- Periodicals; Measurement -- Periodicals; Measurement; Weights and measures; Periodicals; 530.8
• DOI: 10.1016/j.measurement.2017.08.041
• Languages: English
• ISSNs: 0263-2241

Abstract

Highlights: A novel mathematical model for Shape Memory Alloy actuators was developed. This modeling scheme provides high correlations with actual data at low computational costs. A new hybrid model depending on the time derivative of the temperature. Approximation based on sigmoid functions of the model allowed arbitrary order time derivations. Numerical and experimental tests showed the effectiveness of the proposed model. Abstract: This paper presents the development of a hybrid model that describes the temperature, elongation and inner force relationships in a spring Shape Memory Alloy (SMA) actuator. The temperature-inner force relationship obeys a hybrid structure in which a sigmoid function correlates the variation of temperature for the SMA and the force executed by the spring actuator. The hybrid nature of the model describes the regular hysteresis behavior of the SMA. The switching law of the hybrid model depends on the time derivative of the temperature. A multivariable model depending on temperature, and inner and external forces was developed in order to characterize the Shape Memory Effect (SME). A set of experiments was carried out to obtain the parameters used to characterize the model. The application of the Levenberg-Marquardt method resulted in the parametric estimation procedure. An averaged correlation factor of 0.95 between the model response and experimental results justifies the proposed modeling approach.