Sandipan Mishra - Academia.edu (original) (raw)
Papers by Sandipan Mishra
Energy and Buildings, 2014
We present a computer graphics simulation framework to pre-visualize and tune the parameters of a... more We present a computer graphics simulation framework to pre-visualize and tune the parameters of an advanced lighting controller for a given illuminated environment. The objective is to show that the simulation framework makes it easy for a user to predict the controller's behavior and modify it with minimal effort. Our methodology involves off-line pre-computation of lightmaps created from photorealistic rendering of the scene in several basis lighting configurations, and the subsequent combination of these lightmaps in a video game engine. We demonstrate our framework in a series of experiments in a simulation of a conference room currently under physical construction, showing how the controller can be easily modified to explore different lighting behaviors and energy use tradeoffs. The result of each experiment is a computer-generated animation of the lighting in a room over time from a single viewpoint, accompanied by estimated measurements of source input, light sensor output, and energy usage. A secondary objective is to match the simulation as closely as possible to a real physical environment with physical electric light sources and sensors. We demonstrate this calibration in a highly-controlled lighting research environment, showing how measurements of source and sensor specifications enable the output of the virtual sensors in the simulation to match the outputs of real sensors in the physical room when applying the same control law in both cases. Our research is aimed at both lighting designers seeking to quantitatively predict real-world controller behavior, and control algorithm researchers seeking to visualize results and explore design tradeoffs in realistic use cases. Furthermore, these simulation tools can aid in the benchmarking of candidate daylighting and lighting control algorithms for a given space.
State-of-the-Art feedback control of lighting depends on point sensor measurements for light fiel... more State-of-the-Art feedback control of lighting depends on point sensor measurements for light field generation. However, since the occupant's perception depends on the entire light field in the room instead of the illumination at a limited set of points, the performance of these lighting control systems may be unsatisfactory. Therefore, it is critical to reconstruct the light field in the room from point sensor measurements and use it for feedback control of lights. This paper presents a framework for using graphical rendering tools along with point sensor measurements for the estimation of a light field and using these estimates for feedback control. Computer graphics software is used to efficiently and accurately model building spaces, while a game engine is used to render different lighting conditions for the space on the fly. These real-time renderings are then used together with sensor measurements to estimate and control the light field in the room using an optimization-based feedback control approach. We present a set of estimation algorithms for this purpose and analyze their convergence and performance limitations. Finally, we demonstrate closed loop lighting control systems that use these estimation algorithms and compare their relative performance, highlighting their benefits and disadvantages.
Lighting constitutes a significant portion of building energy consumption. Various lighting contr... more Lighting constitutes a significant portion of building energy consumption. Various lighting control strategies exist that reduce the energy consumption by decreasing dimming level of the fixtures and also ensure the color quality of the achieved light. These strategies differ in their input parameters, control objectives , control algorithms, cost of installation, complexity of commissioning, availability of hardware, etc. Each of these control schemes has a unique set of factors that affect their performance in terms of energy savings as well as the achieved light quality. This paper presents an experimental survey of four state-of-the-art lighting control strategies, the formulation of their associated problems as well as their solution approaches, the experimental results obtained from their implementation in a standard testbed, and the factors affecting their performances.
Energy and Buildings, 2014
We present a computer graphics simulation framework to pre-visualize and tune the parameters of a... more We present a computer graphics simulation framework to pre-visualize and tune the parameters of an advanced lighting controller for a given illuminated environment. The objective is to show that the simulation framework makes it easy for a user to predict the controller's behavior and modify it with minimal effort. Our methodology involves off-line pre-computation of lightmaps created from photorealistic rendering of the scene in several basis lighting configurations, and the subsequent combination of these lightmaps in a video game engine. We demonstrate our framework in a series of experiments in a simulation of a conference room currently under physical construction, showing how the controller can be easily modified to explore different lighting behaviors and energy use tradeoffs. The result of each experiment is a computer-generated animation of the lighting in a room over time from a single viewpoint, accompanied by estimated measurements of source input, light sensor output, and energy usage. A secondary objective is to match the simulation as closely as possible to a real physical environment with physical electric light sources and sensors. We demonstrate this calibration in a highly-controlled lighting research environment, showing how measurements of source and sensor specifications enable the output of the virtual sensors in the simulation to match the outputs of real sensors in the physical room when applying the same control law in both cases. Our research is aimed at both lighting designers seeking to quantitatively predict real-world controller behavior, and control algorithm researchers seeking to visualize results and explore design tradeoffs in realistic use cases. Furthermore, these simulation tools can aid in the benchmarking of candidate daylighting and lighting control algorithms for a given space.
State-of-the-Art feedback control of lighting depends on point sensor measurements for light fiel... more State-of-the-Art feedback control of lighting depends on point sensor measurements for light field generation. However, since the occupant's perception depends on the entire light field in the room instead of the illumination at a limited set of points, the performance of these lighting control systems may be unsatisfactory. Therefore, it is critical to reconstruct the light field in the room from point sensor measurements and use it for feedback control of lights. This paper presents a framework for using graphical rendering tools along with point sensor measurements for the estimation of a light field and using these estimates for feedback control. Computer graphics software is used to efficiently and accurately model building spaces, while a game engine is used to render different lighting conditions for the space on the fly. These real-time renderings are then used together with sensor measurements to estimate and control the light field in the room using an optimization-based feedback control approach. We present a set of estimation algorithms for this purpose and analyze their convergence and performance limitations. Finally, we demonstrate closed loop lighting control systems that use these estimation algorithms and compare their relative performance, highlighting their benefits and disadvantages.
Lighting constitutes a significant portion of building energy consumption. Various lighting contr... more Lighting constitutes a significant portion of building energy consumption. Various lighting control strategies exist that reduce the energy consumption by decreasing dimming level of the fixtures and also ensure the color quality of the achieved light. These strategies differ in their input parameters, control objectives , control algorithms, cost of installation, complexity of commissioning, availability of hardware, etc. Each of these control schemes has a unique set of factors that affect their performance in terms of energy savings as well as the achieved light quality. This paper presents an experimental survey of four state-of-the-art lighting control strategies, the formulation of their associated problems as well as their solution approaches, the experimental results obtained from their implementation in a standard testbed, and the factors affecting their performances.