Robust Navigation in Multipath Environments Using GNSS/UWB/INS Integration with Anchor Position Estimation Toward...

Area of Science:

• Navigation Systems Engineering
• Robotics and Autonomous Systems
• Geomatics Engineering

Background:

• Global Navigation Satellite Systems (GNSS) are crucial for autonomous vehicles and urban air mobility but struggle with accuracy in complex environments due to multipath interference.
• Multipath effects, signal blockage, and attenuation from urban structures severely degrade GNSS positioning performance, posing risks to safety-critical applications.
• Existing ultra-wideband (UWB) systems require precise pre-surveyed anchor locations, limiting their deployment flexibility.

Purpose of the Study:

• To develop and evaluate a loosely integrated navigation framework combining GNSS, UWB, and Inertial Navigation System (INS) data.
• To enhance positioning accuracy and robustness in GNSS-degraded environments, specifically addressing multipath effects.
• To enable UWB anchor self-localization, reducing reliance on pre-surveyed infrastructure.

Main Methods:

• A loosely coupled navigation filter was designed integrating GNSS, UWB, and INS sensor data.
• UWB ranging measurements were utilized, with an extended approach for estimating UWB anchor positions.
• Field experiments were conducted using a drone in multipath-prone outdoor urban settings.

Main Results:

• The proposed GNSS/UWB/INS integration achieved up to a 90% reduction in positioning errors compared to GNSS/INS alone.
• Submeter-level positioning accuracy was demonstrated in areas with sufficient UWB anchor coverage.
• The system exhibited significant robustness against multipath interference inherent in urban canyons.

Conclusions:

• The integrated GNSS/UWB/INS navigation framework offers a robust solution for accurate positioning in challenging urban environments.
• The ability to estimate UWB anchor locations alleviates a key deployment barrier, enhancing UWB system utility.
• This approach provides a pathway towards reliable navigation for future applications like electric Vertical Take-Off and Landing (eVTOL) aircraft.