Real-Time Energy Audit of Built Environments: Simultaneous Localization and Thermal Mapping

Abstract

Leveraging thermography for managing built environments has become prevalent as a robust tool for detecting, analyzing, and reporting their performance in a nondestructive manner. Despite many documented benefits of thermographic inspection for better characterizing the conditions of built environments, current thermographic inspections still have several inefficiencies. Inspectors typically collect and store large numbers of thermal images or long-sequence thermal videos to support decision making on the maintenance and rehabilitation of built environments. However, more importantly, these large-scale visual data are typically unordered and not localized (a term used to define a process of finding locations or relative positions of a camera). This paper proposes and compares two approaches for simultaneous localization and thermal mapping. These methods estimate a camera’s pose and map the environment in three dimensions in real-time. Case studies using an off-the-shelf hardware configuration using solely thermal cameras and an author-customized configuration using both thermal and red, green, and blue (RGB) cameras are conducted and the results are compared with a well-established offline three-dimensional mapping tool. The results show that combining information from RGB and thermal cameras provides significant benefits to real-time localization compared with using solely thermal cameras and that the proposed real-time methods have localization performance comparable to the offline tool.