An Automatic Mobile Sensing Platform for Indoor Environmental Quality Assessments

 Since the advent of the COVID-19 pandemic, the amount of time that individuals spend indoors has increased to approximately 95%, emphasizing the need for indoor environments that promote health and productivity. However, few communities are aware of the connection between the critical importance of Indoor Environmental Quality (IEQ) and the health, productivity, and comfort of the occupants, as well as the collective performance of an organization. As a result, most public buildings, especially school buildings, fail to meet the minimum IEQ standards required by building codes and are generally far below the recommended levels by many health agencies. 

To improve IEQ conditions, the first step is to measure, monitor, and evaluate the current IEQ conditions of the target buildings. IEQ assessments include two components: quantitative measurements of physical attributes and qualitative occu?pant satisfaction surveys. Quantitative measurements and monitoring of physical attributes include indoor air quality (IAQ), thermal quality, lighting quality, acoustic quality, and spatial quality. Currently, qualitative occupant satisfaction surveys aim to collect subjective feedback from occupants on IEQ-related issues in the built environment. 

Traditional methodologies for assessing IEQ from both objective and subjective perspectives present certain limitations. In the case of objective assessments, which involve measuring and monitoring IEQ physical attributes, the field measurement process requires substantial time and effort. This is due to the necessity for practitioners and researchers with specialized knowledge of IEQ to operate handheld devices to gather data. In addition, monitoring IEQ attributes is typically based on a stationary sensor network, which is limited in its ability to accurately represent the spatial characteristics of IEQ attributes due to its sparse nature. In terms of subjective evaluations, conventional methods include surveys, questionnaires, interviews, and direct observations. Although these techniques provide valuable insights into the perceptions of the occupants, they are inherently time-consuming and costly and necessitate the involvement of experts to conduct the assessments. Furthermore, traditional post-occupation evaluation (POE) approaches lack effective strategies to promote occupant engagement and awareness, potentially limiting the quality and quantity of input gathered from building occupants. 

In light of these limitations, it is imperative to develop alternative approaches to IEQ assessments that streamline the process, improve spatial representation, and encourage higher levels of participation of the occupant. To address the aforementioned challenges associated with conventional IEQ assessments, this thesis introduces an innovative automated mobile platform to facilitate simultaneous, continuous, and autonomous evaluation of IEQ conditions. The proposed system incorporates a variety of equipment, including thermal infrared cameras, RGB and depth cameras, as well as an array of specialized IEQ sensors for monitoring thermal comfort, Indoor Air Quality (IAQ), lighting levels, and acoustics. The platform incorporates the comprehensive suite of sensors into simultaneous localization and mapping (SLAM) and utilizes Gaussian process modeling with progressively observed measurements to deliver high-resolution spatiotemporal monitoring of IEQ physical attributes, thereby overcoming the limitations of traditional stationary sensor networks. Furthermore, the proposed platform incorporates a framework designed to assess mean radiant temperature (MRT), a parameter that has proven challenging to measure using conventional methodologies. The platform also integrates a social robot to conduct qualitative post-occupancy evaluations (POE) and collect satisfaction feedback from building occupants. This innovative approach not only streamlines the data collection process but also enhances occupant engagement, ensuring more accurate and comprehensive assessments. The proposed platform aims to improve existing IEQ conditions to improve the occupants’ comfort, health, well-being, and performance. By providing a more comprehensive understanding of the indoor environment, the platform enables stakeholders to make informed decisions that reduce energy costs and contribute to a safer and more comfortable indoor environment.