“Just Follow the Lights”: A Ubiquitous Framework for Low-Cost, Mixed Fidelity Navigation in Indoor Built Environments

Highlights

• A low-cost system for indoor navigation with a lightweight and open deployment paradigm as well as a novel map ingestion mechanism

• A formative study that explores current perceptions of existing navigation solutions while also reaffirming the need for additional navigational support in everyday buildings

• A controlled study that evaluates performance and the interaction of display density and route complexity against an existing baseline

• Design recommendations for deploying such systems in the built environment to foster new interactions in buildings.

• A system of networked LED indicators can improve both wayfinding performance and experience, boosting confidence and consistency among users while delivering similar benefits as high-cost digital alternatives.

Abstract

Indoor navigation is an important daily task in a variety of contexts (e.g., offices, hospitals, airports). However, navigational ease is not always considered when buildings are designed, making wayfinding a difficult and frustrating experience. Moreover, existing solutions are expensive, highly specialized, or both. In this work, we examine how a system of connected low-cost displays designed as an open API can be leveraged to guide users to their destinations quickly, easily, and with minimal cognitive load. Following a formative survey (N=58), we designed: (i) a system of linked, low-fidelity indicators, (ii) a novel map ingestion mechanism for quick and easy deployment, and (iii) a framework for controlling and interacting with an ecosystem of mixed-fidelity devices. We then evaluated our system through a controlled user experiment (N=18) that explores the impact of indicator density and route complexity on performance. Our work shows low-cost embedded indicators can improve indoor navigational experiences by delivering many of the same benefits as more costly solutions, we argue that such indicators would complement existing navigational solutions in a mixed-fidelity ecosystem, and we discuss use-cases as well as design recommendations for deploying similar systems.

Introduction

Indoor navigation is an important daily task for many people in a variety of contexts (e.g., offices, hospitals, airports). Despite its importance, navigational ease is often compromised when a new building is designed due to practical considerations such as construction costs, aesthetics, or utility (i.e., structural concerns, routing of electrical, HVAC, etc.), which may inform the layout more than usability does Seidel and Rappaport (1994). This often makes wayfinding (i.e., the act of orienting one’s self in a space, planning a route, and traveling to a destination) a difficult and frustrating experience Arthur and Passini (1992). The downstream impact of these decisions in building layout can result in inefficient workflows, wasted time, and users becoming dissatisfied with their experience in these spaces Zimring (1990). However, the advent of interactive digital signage and the proliferation of the Internet-of-Things (IoT) presents new opportunities for creating smoother, more streamlined navigational experiences Ashton et al. (2009). We envision a rich ecosystem of varying fidelity devices, communicating via open APIs and coordinating their actions to support a wide range of functionality and interactivity. This system, aware of user presence, needs, and preferences, could, among other things, guide them through a complex space by displaying directions along their route.

Previous work on indoor navigational support has focused on the cognitive factors of wayfinding Golledge (1999), solutions to technical challenges like localization Fallah et al. (2013) or navigating without GPS Brush et al. (2010), and evaluating systems geared toward supporting different user populations from everyday pedestrians Müller et al. (2008); Rukzio et al. (2009) to populations with accessibility concerns A. Karimi et al. (2014); Ahmetovic et al. (2016); Chang and Wang (2010); Fixova et al. (2014); Liu et al. (2008); Zhang et al. (2008). These works lay a strong foundation for the exploration of wayfinding challenges, but the literature also tend to focus on: (i) navigation solutions that utilize large and costly public displays Coenen et al. (2016); Kray, Cheverst, Fitton, Sas, Patterson, Rouncefield, Stahl, 2006, Kray, Cheverst, Harrison, Hamhoum, Wagner, 2008, special purpose mobile applications Arthur and Passini (1992); Brush et al. (2010); Roy et al. (2017), or large quantities of Bluetooth beacons Huang et al. (2009), (ii) contexts such as transportation hubs Coenen et al. (2016); Kataoka et al. (2016) or outdoor spaces Rukzio et al. (2009), and (iii) displaying other informational content like advertisements or inter-office messages Coenen et al. (2016); Kray et al. (2006). Evaluations of such systems have also been mixed, with many providing support for the user’s sense of navigational ease but not resulting in significant performance improvements over existing baselines in controlled studies. This is problematic as such systems are costly for everyday use-cases.

Toward addressing these limitations, we explore how a connected set of low-cost displays can be leveraged to guide users to their destinations quickly, easily, and with minimal cognitive load (see Figure 1 and Supplemental Video). We theorize that such a solution could be used independently or to augment existing systems, with the overarching goal of creating a scalable, connected, and coordinated ecosystem of devices working together intelligently to guide users. As a proof of concept, we designed a system of linked, low-fidelity indicators, a novel map ingestion mechanism to quickly and easily deploy such a system, and a framework for controlling and interacting with an ecosystem of mixed-fidelity devices. In this work, our research questions include: How can we design a low-cost system that improves indoor navigational performance while keeping users engaged in their environment? What impact does display density and route complexity have on performance? And, what does this mean for the scalability of such systems?

To answer these questions, we conducted a multi-stage study with 58 participants recruited from a software company that focused on navigation in a large and active office environment. We started by conducting a survey to determine the types of navigational challenges experienced by our population and to inform our system design. We then designed a prototype navigation system built with inexpensive off-the-shelf parts and evaluated it using a mixed-methods approach, including a controlled user experiment and semi-structured interview (N=18). Our results show that a low-cost system of networked LED indicators can improve the wayfinding experience without the need for larger, more expensive, high-fidelity hardware, boosting confidence and leading to faster, more reliable, and more consistent user performance. The direct contributions of this work include: (i) a low-cost system for indoor navigation with a lightweight and open deployment paradigm as well as a novel map ingestion mechanism, (ii) a formative study that explores current perceptions of existing navigation solutions while also reaffirming the need for additional navigational support in everyday buildings, (iii) a controlled study that evaluates performance and the interaction of display density and route complexity against an existing baseline, and (iv) design recommendations for deploying similar systems.