The position of persons or goods in 3D space is a crucial information for different types of applications. In the realm of Wireless Sensor Networks (WSNs), the position of individual sensor nodes can be exploited to enable applications like location-based routing or positioning of vehicles. Most Real-Time Locating Systems (RTLS) are based on measurements of Received Signal Strength Indication (RSSI), Time-of-Flight (ToF) or Angle-of-Arrival (AoA). This often requires additional hardware.
InPhase Sensor Node
InPhase does not require additional hardware except for a radio transceiver with integrated Phase Measurement Unit (PMU). The system determines the distance between pairs of nodes in the sensor network. By adding nodes with known positions to the network, the absolute 3D position of a sensor node can be computed.
Currently, the system employs the AT86RF233, an IEEE 802.15.4 radio transceiver. This chip by Atmel (Microchip) features an integrated PMU to measure the phase angle of an incoming radio wave. This extra information allows to determine the distance between sender and receiver. InPhase implements the execution of such a phase measurement. The resulting phase data is used to compute the distance between the two devices. Additionally, we investigated the quality of the measurement data in different environmental conditions.
Measured Phase Data
To allow easy integration of InPhase into other applications, the network protocol and algorithm are implemented based on the Contiki operating system by Dunkels et al. We use different variants of the INGA wireless sensor node as hardware platform. Additionally, we developed a PC software that allows to initiate measurements and to evaluate the obtained measurement data. This software also implements positioning via a Particle Filter. To mitigate the effect of errorneous measurements, the software uses additional metrics to determine the quality of a distance measurement.
Localization via Particle Filter
| Name | Phone | Room | |
|---|---|---|---|
| Dr. Yannic Schröder | schroeder[[at]]ibr.cs.tu-bs.de | ||
| Prof. Dr.-Ing. Lars Wolf | wolf[[at]]ibr.cs.tu-bs.de | +49-531-3913288 | 138 |
| Title | Type | Supervisor | Status |
|---|---|---|---|
| InPhase, ... | Master Thesis | Prof. Dr. Felix Büsching, Stephan Rottmann, Dr. Georg von Zengen | finished |
| Implementation of a system to create light paintings with a cable robot | Project Thesis | Dr. Yannic Schröder | finished 2020 |
| Einfluss der Antennen, ihrer Ausrichtung und von Reflexionen auf die Genauigkeit des InPhase-Systems | Bachelor Thesis | Dr. Yannic Schröder | finished ~2017 |
| Analyse und Verbesserung des InPhase-Systems | Bachelor Thesis, Master Thesis, Project Thesis | Dr. Yannic Schröder | finished |
| Adapting InPhase for large indoor networks | Master Thesis | Dr. Yannic Schröder | finished 2020 |
| Parallelisierte Messung von Phasengängen zur Lokalisation | Master Thesis | Dr. Yannic Schröder | finished ~2019 |
| Analyse von phasenbasierten Entfernungsmessungen bei Nicht-Sichtverbindungen und Mehrwegeausbreitung | Master Thesis | Dr. Yannic Schröder | finished ~2018 |
| Implementation and evaluation of a particle filter for the InPhase system | Master Thesis | Dr. Yannic Schröder, Prof. Dr. Felix Büsching | finished ~2016 |
| Analyse des InPhase-Systems zur Verbesserung von Präzision und Genauigkeit | Master Thesis | Dr. Yannic Schröder | finished ~2017 |
| Modularization and Generalization of the InPhase-System for Different Platforms | Master Thesis | Dr. Yannic Schröder | finished ~2019 |
| Implementierung von Software- und Systemtests für das InPhase-System | Project Thesis | Dr. Yannic Schröder | finished ~2017 |
| Statistical approach for the InPhase positioning system | Bachelor Thesis | Dr. Yannic Schröder, Dr. Georg von Zengen, Stephan Rottmann | finished ~2015 |
If you are interested in writing a thesis regarding this project, please feel free to contact Dr. Yannic Schröder.