An Effective Terrain Aided Navigation for Low-Cost Autonomous Underwater Vehicles

Area of Science:

• Robotics
• Navigation Systems
• Ocean Engineering

Background:

• Terrain-aided navigation offers precise underwater positioning for autonomous underwater vehicles (AUVs).
• Limited sensor availability, particularly with low-grade inertial navigation systems, degrades traditional and terrain-aided navigation accuracy.
• Existing methods struggle with sensor limitations, impacting the reliability of AUV positioning.

Purpose of the Study:

• To develop a robust terrain-aided navigation system for AUVs with limited sensor capabilities.
• To enhance the accuracy and reliability of underwater navigation for low-cost AUVs.
• To address the challenge of degraded navigation performance due to sensor limitations.

Main Methods:

• A tightly-coupled navigation approach is proposed, integrating raw sensor data into an augmented navigation system.
• Critical sensor errors are estimated by incorporating raw sensor data directly.
• A particle filter is utilized for measurement updates, calculating three-dimensional distance errors for absolute and bounded position error.
• The system is developed for AUVs equipped with a non-inertial-grade strapdown inertial navigation system, a 4-beam Doppler Velocity Log, and a sonar altimeter.

Main Results:

• The proposed tightly-coupled navigation method successfully estimates critical sensor errors.
• The system provides measurement updates through a particle filter, addressing position errors.
• Experimental data demonstrates significant improvements in navigation performance for low-cost AUVs.
• The method proves effective across diverse terrain characteristics.

Conclusions:

• The developed terrain-aided navigation system effectively overcomes limitations of low-grade sensors.
• This approach significantly enhances the navigation performance of low-cost AUVs.
• The method offers a viable solution for accurate submerged position fixing in challenging underwater environments.