Accuracy Evaluation of Selected Mobile Inspection Robot Localization Techniques in a GNSS-Denied Environment

Area of Science:

• Robotics
• Geomatics
• Sensor Fusion

Background:

• Accurate robot localization is crucial for inspection missions and spatial data acquisition, especially in GNSS-denied environments like urban or underground settings.
• Environmental parameter measurements gain significant value when spatially referenced, enabling deeper analysis.
• Traditional Global Navigation Satellite Systems (GNSS) are often unavailable in these operational conditions, necessitating alternative positioning solutions.

Purpose of the Study:

• To assess and compare the positioning accuracy of mobile robots using various methods independent of GNSS signals.
• To evaluate the suitability, advantages, and disadvantages of different localization techniques for autonomous robotic systems in underground mine environments.

Main Methods:

• Utilized automated geodetic surveying equipment for precise ground truth data acquisition.
• Compared positioning accuracy of four methods: wheel odometry, inertial measurement-based dead-reckoning, visual odometry, and ultra-wideband (UWB) signal trilateration.

Main Results:

• Wheel odometry and inertial measurement-based dead-reckoning exhibited limitations in accuracy for long-term navigation.
• Visual odometry demonstrated robust performance in feature-rich environments.
• Ultra-wideband trilateration provided high accuracy but required specific infrastructure setup.

Conclusions:

• No single GNSS-independent method is universally optimal; the choice depends on the specific application requirements and environmental constraints.
• Visual odometry and UWB trilateration are promising for accurate robot localization in GNSS-challenged underground environments.
• Further research is needed to optimize sensor fusion techniques for enhanced robustness and accuracy in complex subterranean conditions.