Improved position control of shape memory alloy actuator using the self-sensing model

Hao

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2022

In this paper, a novel data-driven model-free adaptive fractional-order sliding mode controller with prescribed performance is proposed for the shape memory alloy (SMA) actuator. Due to the strong asymmetric saturated hysteresis nonlinear characteristics of the SMA actuators, it is not easy to establish an accurate model and develop an effective controller. Therefore, we present a controller without using the model of the SMA actuators. In other words, the proposed controller depends merely on the input/output (I/O) data of the SMA actuators. To obtain the reasonable compensation for hysteresis, enhance the noise robustness of the controller, and reduce the chattering, a fractional-order sliding mode controller with memory characteristics is employed to improve the performance of the controller. In addition, the prescribed performance control (PPC) strategy is introduced in our work to guarantee the tracking errors converge to a sufficiently small boundary and the convergence rate is not less than a predetermined value which are significant and considerable in practical engineering applications of the SMA actuator. Finally, experiments are carried out, and results reveal the effectiveness and success of the proposed controller. Comparisons with the classical Proportional Integral Differential (PID), model-free adaptive control (MFAC), and model-free adaptive sliding mode control (MFAC-SMC) are also performed.

Section: Prescribed Performance Controlmentioning

confidence: 99%

“…As can be seen from equation (16), if e k approaches the upper bound ρ k or lower bound Àρ k , μ k will change drastically and tends to infinity. Therefore, if we can guarantee the boundedness of μ k in the initial condition which satisfies À ρ 0 < e 0 < ρ 0 , then the error is constrained within the range (11).…”

Section: Prescribed Performance Controlmentioning

confidence: 99%

Data-driven model-free adaptive fractional-order sliding mode control for the SMA actuator with prescribed performance

Hao

Proceedings of the Institution of Mechanical Engineers, Part C:

et al. 2022

Journal of Intelligent Material Systems and Structures

“…However, the metal wires cannot be properly removed from the polyimide tubes embedded in the STFHC structures due to the jamming between the tubes and the wires after the autoclave process. Thus, we used ''shape memory alloy (SMA) wire (Lee and Kim, 2019)'' with a diameter of 0.38 mm instead of conventional metal wires because the SMA shrinks and slips in the polyimide tube at the curing temperature. Lubricant was also applied on the surface of the SMA wires in order to be easily removed from the polyimide tubes.…”

Section: Propertiesmentioning

confidence: 99%

Enhanced damping characteristics of carbon fiber reinforced polymer–based shear thickening fluid hybrid composite structures

Lim

Kim

2020

Self Cite

Lightweight carbon fiber reinforced polymer composite structures with high stiffness are at risk of resonant vibration. Our study proposes a methodology to reduce this risk by passively improving the damping ratio of carbon fiber reinforced polymer composite structures. We developed shear thickening fluid hybrid composite structures by applying polyimide tubes filled with shear thickening fluid having rheological properties into a composite laminate. In order to verify the proposed methodology, carbon fiber reinforced polymer–based shear thickening fluid hybrid composite beams were fabricated, and modal tests were subsequently performed to investigate their dynamic characteristics. The results revealed that the damping ratios for the initial six vibration modes of the carbon fiber reinforced polymer–based shear thickening fluid hybrid composite beam increased by 38%–174%; however, their Young’s modulus and tensile strength, respectively, decreased by 11.25% and 14.08% when compared to those of normal carbon fiber reinforced polymer composite beams. We believe that the proposed methodology to improve the damping ratio will contribute in reducing the risk of vibration resonance of carbon fiber reinforced polymer composite structures in various applications.

“… Smart materials : SMs are those materials, which are sensitive to a particular stimulus and tend to change its state once exposed to that stimulus. They are classified into various categories (Bogue, 2014) based on their capabilities, namely, shape-changing (Tibbits, 2014), self-actuating (Wu et al , 2020), self-sensing (Lee and Kim, 2019b), self-diagnostic (Son, 2014) and self-healing (Bai, 2020; Liu, 2018a; Darabi, 2017). Each material exhibits a different behaviour or response when exposed to their suitable stimulus.…”

Section: Introductionmentioning

confidence: 99%

Functional applications of 4D printing: a review

Mohol

Sharma

2021

RPJ

Purpose Additive manufacturing has rapidly developed in terms of technology and its application in various types of industries. With this rapid development, there has been significant research in the area of materials. This has led to the invention of Smart Materials (SMs). The 4D printing is basically 3D printing of these SMs. This paper aims to focus on novel materials and their useful application in various industries using the technology of 4D printing. Design/methodology/approach Research studies in 4D printing have increased since the time when this idea was first introduced in the year 2013. The present research study will deeply focus on the introduction to 4D printing, types of SMs and its application based on the various types of stimulus. The application of each type of SM has been explained along with its functioning with respect to the stimulus. Findings SMs have multiple functional applications pertaining to appropriate industries. The 4D printed parts have a distinctive capability to change its shape and self-assembly to carry out a specific function according to the requirement. Afterward, the fabricated part can recover to its 3D printed “memorized” shape once it is triggered by the stimulus. Originality/value The present study highlights the various capabilities of SMs, which is used as a raw material in 4D printing. Graphical abstract