Open Access Open Access  Restricted Access Subscription Access

Active Shape Control of Parabolic Antenna Systems Using Shape Memory Alloy (SMA)

Praveen Kumar, Bishakh Bhattacharya

Abstract


Active shape control of flexible antenna structures has become highly demanding in the antenna community. This is due to multiple advantages of control of thermal fluttering and reconfigurability of the antenna. It also enables the antenna to get uniquely shaped against any complicated / irregular footprint. In this work, an effort was made to understand and implement active shape control of various sizes of antenna using Shape Memory Alloy (SMA) wire as actuators. It has been demonstrated that a polycarbonate parabolic antenna surface fitted with curved acrylic stiffeners at the back could be actively deformed by a network of SMA wires. The phase transformation of SMA wires results in the generation of end moment and force at the control points. This can deform the stiffener and thereby the antenna structure. This procedure can generate a maximum deflection greater than 3mm (3000 μm) at the pre-defined control points and can be used for macro shape control. By controlling the current in the SMA wires selectively one can achieve both inward and outward deflection. For numerical study, experiments were conducted to understand the physical properties of these SMA wires and an Equivalent Coefficient of Thermal Expansion (ECTE) model was built for use in numerical simulations. Temperature of the SMA wire was measured during experiments by J-type thermocouple. Later, these temperatures were used to apply necessary boundary conditions in numerical study using ABAQUS. Antenna deflections at a couple of control points were studied experimentally and numerically. Both results were compared and inferences were drawn on the discrepancies. A closed loop system was proposed using a proportional-integral-derivative (PID) control system applicable in real-time with the aid of dSPACE unit. With the help of Ziegler-Nichols method, gains were predicated and the response of the system was captured. This work is envisaged to enable us to design deformable antenna which can be reconfigured for various control point deflections.

Full Text:

PDF

References


. de Weck, O., Miller, D., and Hansman, J., “Adaptive Technique for Radiation Pattern Shaping of Parabolic Mesh Antennae: A low cost application of SMA actuators in spacecraft,” ACTUATOR 98. 6th International Conference on New Actuators with Accompanying Exhibition, Proceedings, Bremen, DE, 17-19 Jun, 1998, pp. 515-520.

. Marc R. Angelino and Gregory N. Washington. 2002, Design and Construction of a Piezoelectric Point Actuated Active Aperture Antenna. Journal of Intelligent Material Systems and Structures, Vol. 13, No. 2-3, Feb 2002, pp. 125-136. doi: 10.1177/104538902761402521

. William B. Cross., Anthony H. Kariotis., and Frederick J. Stimler., “Nitinol Characterization Study,” U.S. National Aeronautics and Space Administration, Vol. 1433, 1969, pp. 26-43.

. Hartl, D. J., Lagoudas, D. C., Calkins, F. T., and Mabe, J. H., “Use of a Ni60Ti shape memory alloy for active jet engine chevron application: I. Thermomechanical characterization,” Smart Mater. Struct, Vol. 19, No. 1, 14 Dec. 2009, pp. 1-18. doi:10.1088/0964-1726/19/1/015020

. Travis, L. Turner., “A New Thermoelastic Model for Analysis of Shape Memory Alloy Hybrid Composites,” Journal of Intelligent Material Systems and Structures, Vol. 11, No. 5, May 2000, pp. 382-394. doi: 10.1106/DTFJ-UFL3-XV0U-WJNA

. Travis, L. Turner., “Experimental validation of a thermoelastic model for SMA hybrid composites,”. SPIE, Smart Structures and Materials; Modeling, Signal Processing, and Control in Smart Structures, Vol. 4326, Paper No. 24, Newport Beach, CA, 21 Aug, 2001, pp. 1-12. doi:10.1117/12.436475

. Brian Davis., Travis, L. Turner., and Stefan Seelecke., “Measurement and Prediction of the Thermomechanical Response of Shape Memory Alloy Hybrid Composite Beams,” SPIE, Smart Structures and Materials; Modeling, Signal Processing, and Control in Smart Structures, Vol. 5757, Paper No. 74, Bellingham, WA, 23 May, 2005. pp. 1-12. doi:10.1117/12.614140

. Lagoudas, D. C., Zhonghe, Bo., Muhammad, A. Qidwai., and Pavlin, B. Entchev., “ SMA UM: User Material Subroutine for Thermomechanical Constitutive Model of Shape Memory Alloys,” 2003. URL: http://smart.tamu.edu/SMAText/. [cited 21 Aug. 2013].

. Hartl D. J, Mooney J.T, Lagoudas D. C, Calkins F. T and Mabe J. H., “Use of a Ni60Ti shape memory alloy for active jet engine chevron application: II. Experimentally validated numerical analysis,” Smart Mater. Struct. Vol. 19, No. 1, 14 Dec. 2009, pp. 1-18. doi:10.1088/0964-1726/19/1/015021

. Dynalloy, Inc. Makers of Dynamic Alloys for Electrically Driven Applications, Tustin, CA. URL: http://www.dynalloy.com/TechDataWire.php. [cited 21 Aug. 2013].

. Sagnik Sarkar, Prof. S. Sangal and Prof. K. Mondal, “Transformation Kinetics of Shape Memory Alloys,” under “Summer Undergraduate Research Grant for Excellence (SURGE) program,” Poster Presentation, DSC 0301, Indian Institute of Technology Kanpur, 2012. URL: http://www.iitk.ac.in/surge/photos_12/

. ASTM F2004-05, Reapproved 2010. Standard Test Method for Transformation Temperature of Nickel-Titanium Alloys by Thermal Analysis.




DOI: http://dx.doi.org/10.21535%2FProICIUS.2013.v9.221

Refbacks

  • There are currently no refbacks.