Autonomous underwater vessels (AUV), also famously known as unmanned undersea vehicles, are a type of deep sea vessel which navigates on its own. Technically a type of robot, an AUV is self-propelled and preprogrammed, and performs it various functions without any human control.
An autonomous underwater vessel is made of several advanced technologies. It is mainly used for under water surveillance, deep sea research, or rescue operations. AUVs are used around the world for various purposes such as harbor and border protection and security, under water mine surveys, ship hull surveys, and gas and pipeline security and surveys.
Image Credit : AUV at Freewebs website (https://www.freewebs.com/ythandesign/auv%2010.jpg)
All AUVs have an integral navigation and control system which works without any human participation. They carry various types of sensors, cameras, and spot lights, along with a GPS system. Apart from this, AUVs also carry sonar, which helps in various functions such as detecting divers, tracking targets, and collecting different underwater parameters. In this way, the AUV can measure the depth, speed, length, and various other specifications of the desired target. AUV collects all these information and sends it to a control and command center located on the shore.
The construction of an AUV is similar to that of a submarine. A small AUV looks like a missile and has a small propeller at the rear for propulsion. A pair of fins is also provided at the sides for stabilization and changing directions. AUVs have a streamlined shape which facilitates moving underwater with reduced stresses.
The navigation of AUVs is generally done by two ways, either on a pre-decided path which is programmed in the AUV or through direction provided by the control and command center. The pre-decided path method is generally used in applications such as pipeline monitoring wherein the route and coordinates are already known. AUVs are generally navigated using the underwater acoustic positioning system, wherein the ship or the control and monitor center is taken as the reference position and the positioning of the AUV is calculated on the basis of GPS data of the reference. All the AUVs run on batteries and have a specific operation period, after which they need to be recharged.
Operation of Autonomous Underwater Vessels
An AUV starts working as soon as it is submerged in the water. It works fully automatically, detecting the target on the basis of the reverberation and noise frequency generated by the latter, and on the basis of the pre-programmed settings. All functions such as detection, tracking, and measuring of various parameters are done without any operator’s interference or inputs.
Once the data is collected by the sensors and cameras of the AUV, it is transmitted to the control center via wireless LAN. The data is transferred on a real time basis so that the operators are able to see live footage taken from the AUVs CCTV cameras.
Image Credits : AUV launching from xpda website (https://xpda.com/junkmail/junk187/auv-retrieval6.jpg)
Application of AUVs – How AUVs are Used
AUVs are generally used by military units or by oil and gas companies. The commercial use of AUVs generally deal with detailed mapping of the ocean floor for building subsea structures, laying pipelines, and for finding appropriate sites for oil and gas exploration.
The military uses AUVs to map a particular area for mines or any unidentified object. AUVs are also used for surveillance of ports and coastal areas. They are also used for detecting submarines and as anti-submarine weapons.
AUVs are also extensively used in the research industry. Scientists need several types of data from the ocean floor or spaces that are inaccessible by human. This type of AUVs has several types of sensors attached to their body that help in collecting different details of the underwater life and ocean floor.