ReLoki: A Light-Weight Relative Localization System Based on UWB Antenna Arrays.

Area of Science:

• Robotics and Autonomous Systems
• Wireless Communication and Sensing

Background:

• Ultra Wide-Band (UWB) sensing is increasingly used for relative localization.
• Current UWB localization often relies on Time of Flight (ToF) with multiple beacons.
• Angle of Arrival (AoA) offers an alternative but less explored UWB localization method.

Purpose of the Study:

• To introduce ReLoki, a UWB platform for 3D relative localization.
• To enable infrastructure-free localization using AoA with UWB antenna arrays.
• To evaluate the performance of different antenna array geometries for AoA-based localization.

Main Methods:

• Developed the ReLoki UWB platform incorporating multi-antenna arrays.
• Designed and tested localization systems using Regular Tetrahedral Array (RTA), Regular Orthogonal Array (ROA), and Uniform Square Array (USA).
• Conducted indoor experiments to assess ranging and AoA-based relative localization accuracy.

Main Results:

• Demonstrated sub-50cm localization errors in indoor experimental studies.
• Achieved localization performance comparable to existing ToF-based systems.
• Validated the feasibility of infrastructure-free relative localization using ReLoki.

Conclusions:

• ReLoki provides an effective platform for infrastructure-free 3D relative localization using UWB AoA.
• AoA-based localization with ReLoki offers a competitive alternative to ToF systems.
• The use of multi-antenna arrays is key to enabling onboard, infrastructure-free localization.