AUV Acoustic Return Navigation for Suspended Underwater Work
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Solution Overview
Problem
Autonomous underwater vehicles (AUVs) face challenges in accurately navigating back to the vicinity of a suspended work position due to accumulated measurement errors in inertial navigation systems, making it difficult to return accurately from a surface ship or underwater station.
Innovation Solution
The method involves dropping a transponder to the seafloor, using acoustic positioning to determine the work suspended position, and then having the AUV sail back to the transponder for accurate navigation, allowing it to resume work from the correct location.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If the AUV uses inertial navigation system to measure position and direction before return, then the AUV can autonomously navigate, but measurement errors accumulate over time making it extremely difficult to accurately sail back to the work suspended position
Solution Approach 1:
The patent introduces an inertial navigation system as an intermediary measurement device to track the AUV's position and direction during suspension work. This mediator provides continuous position data that can be used to calculate the return path, though its accuracy degrades over time due to error accumulation. The system complements this with periodic acoustic positioning to reset errors.
Solution Approach 2:
The patent implements feedback through acoustic positioning systems that periodically measure the AUV's actual position relative to fixed acoustic markers on the seabed or ship. This feedback allows the system to detect and correct accumulated inertial navigation errors, resetting the position accuracy before the AUV returns to the work suspension point.
2Duration of action of stationary object
If the AUV reciprocates between the work object and return destination for charging or device replacement, then the AUV can maintain operation continuity, but the work progress is reduced due to repeated travel
Solution Approach 1:
The patent applies preliminary action by having the AUV return to the ship or underwater station before critical failures occur - specifically when battery charge reaches a predetermined threshold or when maintenance is needed. This proactive return strategy prevents work interruption while optimizing the balance between continuous operation and necessary maintenance cycles.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the AUV to accurately sail from the return destination to the vicinity of the work suspended position, improving navigation accuracy and enabling efficient resumption of work.
Implementation Method 1
a step of resuming work on the work object by causing the AUV to sail from the return destination to a vicinity of a work suspended position, at which the work on the work object is suspended, based on information obtained by acoustic positioning using the transponder that is sunk to the bottom of water
Data Source
AI summary
A working method using an AUV includes a step of working on a work object with a work device included in the AUV while causing the AUV to sail along the work object, a step of dropping and sinking a transponder to the bottom of water, a step of causing the AUV to sail toward a return destination, and a step of resuming work on the work object by causing the AUV to sail from a return destination to the vicinity of a work suspended position, at which work on the work object is suspended, based on information obtained by acoustic positioning using the transponder that is sunk to the bottom of water.