PINDOC: Pedestrian Indoor Navigation System Integrating Deterministic, Opportunistic, and Cooperative Functionalities

In this paper, we present a Pedestrian Indoor Navigation system integrating Deterministic, Opportunistic, and Cooperative functionalities (PINDOC) for multi-agent navigation. The deterministic module produces a navigation solution for each agent by utilizing a Zero-velocity-UPdaTe (ZUPT)-aided Inertial Navigation System (INS) augmented with an altimeter and foot-to-foot range measurements. The opportunistic module augments the deterministic solutions with pseudorange measurements extracted from cellular Long-Term Evolution (LTE) signals. The navigation accuracy of each individual agent is further enhanced by cooperative localization using Ultra-WideBand (UWB)-based inter-agent range measurements. We developed a dedicated multi-sensor pedestrian navigation hardware testbed and conducted an experiment to evaluate the navigation performance of different combinations of components comprising PINDOC: ZUPT-aided INS, altimeter, foot-to-foot ranging, LTE signals, and inter-agent ranging. The experiment involved three agents, with one agent traversing a trajectory of 600 meters in 14 minutes, during which, the other two agents remained stationary. The traversed trajectory included terrains of flat surfaces, stairs, ramps, and elevators. The PINDOC system showed high accuracy, achieving a position Root-Mean-Squared Error (RMSE), maximum error, and final error of 0.93 m, 2.23 m, and 1.28 m over the 600-meter trajectory.