Accuracy and Precision Assessment of AoA-Based Indoor Positioning Systems Using Infrastructure Lighting and a Position-Sensitive Detector

Abstract

Unlike GNSS-based outdoor positioning, there is no technological alternative for Indoor Positioning Systems (IPSs) that generally stands out from the others. In indoor contexts, the measurement technologies and localization strategies to be used depend strongly on the application requirements and are complementary to each other. In this work, we present an optical IPS based on a Position-Sensitive Detector (PSD) and exploiting illumination infrastructure to determine the target position by Angle of Arrival (AoA) measurements. We combine the proposed IPS with different positioning strategies depending on the number of visible emitters (one, two, or more) and available prior or additional information about the scenario and target. The accuracy and precision of the proposal is assessed experimentally for the different strategies in a 2.47 m high space covering approximately 2.2 m2, using high-end geodetic equipment to establish the reference ground truth. When the orientation of the target is known from external measurements, an average positioning error of 8.2 mm is obtained using the signal received from only one emitter. Using simultaneous observations from two emitters, an average positioning error of 9.4 mm is obtained without external information when the target movement is restricted to a plane. Conversely, if four signals are available, an average positioning error of 4.9 cm is demonstrated, yielding the complete 3D pose of the target free of any prior assumption or additional measurements. In all cases, a precision (2σ) better than 5.9 mm is achieved across the complete test space for an integration time of 10 ms. The proposed system represents a prospectively useful alternative for indoor positioning applications requiring fast and reliable cm-level accuracy with moderate cost when smart illumination infrastructure is available in the environment.

Weak Calibration of a Visible Light Positioning System Based on a Position-Sensitive Detector: Positioning Error Assessment

“…It is also possible to obtain the position from the signal of only one emitter if the rotation of the agent is already known by means of external methods or sensors. In [ 47 ], the positioning proposals using 1, 2, and 3 or more emitters are shown in detail. This last case allows one to obtain the total pose, i.e., 3D coordinates and three angles that define its orientation.…”

“…When focusing, therefore, on the VLP based on angle of arrival (AoA) measurements, there are different alternatives depending on the types of sensors used; the most relevant are the works based on cameras [ 24 ], QADA sensors [ 45 ], photodiode arrays [ 46 ], and PSDs [ 47 ]. Each of the alternatives has its advantages and disadvantages.…”

“…According with the introduction and considering the background of the existing research on the topic, the work presented here focuses the research on VLP systems based on PSDs. This work is based on the work shown in [ 47 ]. In that work, several proposals were made for LPS based on optical signals from PSDs as a function of the number of emitters within the field of view of the emitter.…”

Time Difference of Arrival Passive Localization Sensor Selection Method Based on Tabu Search

“…In (3), the matrix A and vector b usually contain error components. Thus, Equation (3) can be rewritten as…”

“…The passive localization method does not emit a signal by itself, and only locates and tracks the source based on the signal radiated by the source, which has stronger concealment and survivability than the active positioning method. Several fundamental approaches for implementing a wireless location system, including those based on received signal strength (RSS) [1,2], angle of arrival (AOA) [3,4], time of arrival (TOA) [5,6], time difference of arrival (TDOA) [7][8][9][10], and frequency difference of arrival (FDOA), have been established. The common technique employed for stationary sources are the measurement of TDOAs using a number of spatially separated sensors.…”