This article presents the development of an image-based sun position sensor and the algorithm for how to aim at the Sun precisely by using image processing. Four-quadrant light sensors and bar-shadow photo sensors were used to detect the Sun’s position in the past years. Nevertheless, neither of them can maintain high accuracy under low irradiation conditions. Using the image-based Sun position sensor with image processing can address this drawback. To verify the performance of the Sun-tracking system including an image-based Sun position sensor and a tracking controller with embedded image processing algorithm, we established a Sun image tracking platform and did the performance testing in the laboratory; the results show that the proposed Sun tracking system had the capability to overcome the problem of unstable tracking in cloudy weather and achieve a tracking accuracy of 0.04°.
References
[1]
Hauff, J.; Verdonck, M.; Derveaux, H.; Dumarest, L.; Gammal, A.E.; Llamas, P.; Masson, G. Unlocking the Sunbelt Potential of Photovoltaics; European Photovoltaic Industry Association and Others: Brussels, Belgium, 2010.
[2]
Roadmap for CPV Technology; GTM Research: Boston, MA, USA, 2011.
[3]
Neville, R.C. Solar energy collector orientation and sun tracking mode. Sol. Energy 1978, 20, 7–11.
[4]
Mousazadeh, H.; Keyhani, A.; Javadi, A.; Mobli, H.; Abrinia, K.; Sharifi, A. A review of principle and sun-tracking methods for maximizing solar systems output. Renew. Sustain. Energy Rev. 2009, 13, 1800–1818.
[5]
Lee, C.-Y.; Chou, P.-C.; Chiang, C.-M.; Lin, C.-F. Sun tracking systems: A review. Sensors 2009, 9, 3875–3890.
[6]
Rubio, F.R.; Ortega, M.G.; Gordillo, F.; López-Martínez, M. Application of new control strategy for sun tracking. Energy Conv. Manage. 2007, 48, 2174–2184.
[7]
Dobon, F.; Fernande, V.; Monedero, J.; Valera, P.; Osuna, R.; Acosta, L.; Marichal, G.N. Closed Loop Controller and Sensor for Solar Tracking. Proceedings of the 17th European Photovoltaic Solar Energy Conference, Munich, Germany, 22–26 October 2001.
[8]
Lynch, W.A.; Salameh, Z.M. Simple electro-optically controlled dual-axis sun tracker. Sol. Energy 1990, 45, 65–69.
[9]
Agarwal, A.K. Two axis tracking system for solar concentrators. Renew. Energy 1992, 2, 181–182.
[10]
Kalogirou, S.A. Design and construction of a one-axis sun-tracking system. Sol. Energy 1996, 57, 465–469.
[11]
Roth, P.; Georgiev, A.; Boudinov, H. Design and construction of a system for sun-tracking. Renew. Energy 2004, 29, 393–402.
[12]
Georgiev, A.; Roth, P.; Olivares, A. Sun following system adjustment at the UTFSM. Energy Conv. Manag. 2004, 45, 1795–1806.
[13]
Trebi-Ollennu, A.; Huntsberger, T.; Cheng, Y.; Baumgartner, E.T.; Kennedy, B.; Schenker, P. Design and analysis of a sun sensor for planetary rover absolute heading detection. IEEE Trans. Rob. Autom. 2009, 17, 6.
[14]
Rufino, G.; Grassi, M. Multi-aperture CMOS sun sensor for microsatellite attitude determination. Sensors 2009, 9, 4503–4524.
[15]
Arturo, M.M.; Alejandro, G.P. High-Precision Solar Tracking System. Proceedings of the World Congress on Engineering, London, UK, 30 June–2 July 2010.
[16]
Baranne, A.; Launay, F. Cassegrain: A famous unknown of instrumental astronomy. J. Opt. 1997, 28, 158–172.
[17]
Klevtsov, Y.A. New optical systems for small-size telescopes. J. Opt. 2000, 67, 176–180.
[18]
Lambda Research. Lambda Research: Littleton, MA, USA, 2010.
[19]
Introduction to Resolution and MTF Curves. Available online: http://www.normankoren.com/Tutorials/MTF.html (accessed on 18 April 2013).
[20]
OSLO？ Analysis. Available online: http://www.atmsite.org/contrib/Fejes/Analysis/0SL0analysis.html (accessed on 18 April 2013).
[21]
MTF-Modulation Transfer Function. Available online: http://www.photozone.de/mtf/ (accessed on 18 April 2013).
[22]
HSL Color Solid Cylinder Alpha Lowgamma.png. Available online: http://en.wikipedia.org/wiki/File:HSL_color_solid_cylinder_alpha_lowgamma.png (accessed on 18 April 2013).
[23]
Vincent, O.R.; Folorunso, O. A Descriptive Algorithm for Sobel Image Edge Detection. Proceedings of Informing Science and IT Education Conference, Macon, GA, USA, 12–15 June 2009.
