Autonomous underwater vehicles (AUVs) are a mainstay of the subsea survey industry. With unparalleled speed and accuracy in deep water, they have long been the obvious choice for surveys in inhospitable, deep environments. In light of the current downturn in the oil and gas market and the increasing visibility of autonomous vehicles, such as self-driving cars, AUV technology is poised to break into new markets.
Ironically, it is the downturn in the oil and gas market that now offers the opportunity for technology to penetrate areas that previously were hard to enter. Whether through inertia or reluctance on operators’ parts, the acceptance of new technologies for certain tasks in this industry has, at times, proceeded at a much slower pace than in other industries. With this downturn, operators are now willing to revisit and explore technologies that offer a better value proposition than doing things the “old way.”
AUV operators are constantly striving to prepare their vehicles to perform new tasks. Meanwhile, our customers are looking for faster, more cost-effective ways to complete slow, labor-intensive tasks. These forces, aligned with the visible state of the art in autonomous vehicles, offer the perfect recipe for the use of autonomous underwater technologies. Improvements in sensing technology, coupled with autonomous advances, make AUVs an attractive platform for inspection tasks. Increasing customer confidence in the state of the art for AUVs is driving the two next big advancements: in-field inspection vehicles with hovering capabilities, along with subsea field resident vehicles.
AUVs are carrying more sophisticated sensor suites than ever before. Multi beam Echo sounder resolutions are increasing, supporting both better quality bathymetry and also water column visualization and analysis. Laser line scanners are being installed on AUVs as standard equipment, allowing sub centimeter resolution imaging and measurement of the subsea environment. High-definition still cameras provide extremely high resolution imagery that can be used both for visualization and metrology. Single images can be stitched together to provide a global view of the inspected area.
Concurrent increases in computing power have made it possible to analyze and act on the rich sensor data collected in real time. Building on the same types of technologies that enable self-driving cars, the next-generation AUV can respond to changes in its environment. For example, if a seep is detected during an inspection, the vehicle can autonomously determine that it should perform a more detailed search pattern in that area. This improves data quality and mission efficiency, which translates directly into cost savings.
Pipeline inspection is another emerging technology for AUVs. In the fourth quarter of 2016, Oceaneering is qualifying a pipeline inspection AUV (PIAUV) for commercial use. This vehicle development program has been driven and funded by industry partners looking to fill a technology gap. The PIAUV autonomously tracks a pipeline, ensuring complete sensor coverage of the pipeline at the lower altitudes that provide the highest resolution imaging and bathymetry available. Additionally, the PIAUV responds dynamically to changes in these environments (such as unexpected obstacles), thus avoiding collisions without needing to abort the mission. This technology is expected to offer substantial cost savings over traditional pipeline inspections performed by ROVs, due to a decrease in field time.
Future development lies in hybridizing ROV and AUV technologies. Merging the two paradigms yields a vehicle that is greater than the sum of its parts. A hovering AUV would be untethered and able to perform light intervention, up close inspections, and to safely navigate a cluttered subsea environment. This migrates the pilot’s role to one of supervision and monitoring, reducing the potential for human error. In the long term, this vehicle could be imagined in a subsea resident capacity, tremendously reducing the cost of operations. The subsea resident application has substantial opportunities for technology development, such as in-field power and data connections for real-time control and video. Currently, wet-mate able power connectors are limited in the number of connections before failure. Future inductive systems for power and data transfer would improve the feasibility and reliability of subsea resident solutions.
To summarize, in spite of challenging market conditions, it is an exciting time to be working in the AUV arena. New and enabling technologies are constantly springing up. High-profile autonomous land vehicles and cost-saving measures are driving AUV operators and customers to invest in exciting applications that push the state of the art for vehicles, sensors, and vehicle autonomy.