Adaptive Lighting

Motivated by opportunities in smart lighting, energy efficiency, and ubiquitous sensing, we present the design of polychromatic solid-state lighting controlled using a sensor network. We developed both a spectrally tunable light source and an interactive lighting testbed to study the effects of systems that adjust in response to changing environmental lighting conditions and users' requirements of color and intensity. Using both linear and nonlinear optimization, the setpoints of overdetermined systems (greater than three wavelengths) and the energy consumption of the network are adjusted according to the room's lighting conditions (e.g., lux and color temperature of multiple fixtures). Using these techniques, it is possible to maximize luminous efficacy or the color rendering index for a given intensity and color temperature. We detail the system modeling, design, optical calibration, and control theory required to modulate the luminous output and minimize wasted energy.

publications:

Paradiso, J.A., Aldrich, M., Zhao, N., "Energy-efficient control of solid-state lighting ," SPIE Newsroom, March 25 2011. http://dx.doi.org/10.1117/12.860755

Aldrich, M., Zhao, N., and Paradiso, J., "Energy efficient control of polychromatic solid-state lighting using a sensor network," Proc. SPIE vol. 7784, 778408 (2010). http://dx.doi.org/10.1117/12.860755 slides

Theses:

Aldrich, M., Dynamic Solid State Lighting, Master's Thesis, Massachusetts Institute of Technology (2010).

Zhao, N., Smart Solid-State Lighting Control, Diplom, RWTH Aachen University (2010).

Press:

Chandler, David L. "Illuminating Research." MIT News 19 Nov. 2010

Richard Lai "MIT developing smart adaptive LED lighting system to reduce energy use by up to 90 percent." Engadget 28 Nov. 2010

Talks:

Chandler, David L. "Illuminating Research." MIT News 19 Nov. 2010


Control of two five-wavelength sources using the sensor node to update the equality constraints of the linear program. The sensor node is placed at different points on the table and when the button is pressed, it measures the contribution of both light sources and the ambient light.

Control of phosphor-based fixtures using the sensor node and camera system. In this video, the intensity and color temperature can be set using either the GUI or the sensor node. The illuminance gradient is on the lower left hand corner and the energy profile on the upper right hand corner. The user can use the camera system to select a portion of the video for illumination as well as the sensor node. Closed loop control is also demonstrated. Finally, a time lapse video showing the lighting network adapt to changing ambient light is shown.

Recent smart lighting demo at Ubicomp 2010 in Copenhagen. Example five-wavelength LED array. Results New sensor design The phosphor-based lighting testbed. User working on the closed-loop phosphor-LED testbed. Controlling the two pentachromatic sources using the sensor node. Illustration

Principle Investigator: Joseph Paradiso

Research Group: Responsive Environments group at the MIT Media Lab

Research Assistants: Matt Aldrich, Nan Zhao

Previous Undergraduate Researchers: Ben Lee (2010/11), Akash Badshah (2012), Alex Kiefer (2012)