TECHNICAL FIELD

The embodiments relate to mobile underwater docking systems, as well as autonomous underwater vehicles.

BACKGROUND

Autonomous Underwater Vehicles (AUVs) have seen rapidly expanding usage over the past decade with advances in computation, miniaturization, sensors, and energy storage. Modern AUVs are able to explore the deepest depths of the world's oceans and collect a wide assortment of useful information for commercial, military, and scientific missions. These AUVs are however limited in endurance due to the restricted energy storage capacities of current battery technology. With these limitations, typical AUV endurance is approximately one day with a manual retrieval and recharging process required between missions. The manual retrieval and recharging process necessitates a manned surface vessel to support the AUV, dramatically increasing costs. In open ocean, manned surface vessel costs are in excess of $30,000 USD/day. Despite the large costs, extended AUV missions do occur such as mine detection, Arctic studies and marine geoscience.

One proposed solution to the endurance limitation of AUVs is automated underwater charging stations. These charging stations can be equipped with sources of power either through renewables (solar, wind, wave) or shore power, meaning that they can support charging AUVs indefinitely. Using existing technology, some AUVs are able to operate for extended periods away from manned surface vessels. These existing stations however are limited in their adaptability to other platforms, are costly to install, and are unable to be modified for mobile applications. Additionally, the infrastructure to support persistence is fixed which is not suitable for transient or expansive missions.

Docking stations for autonomous underwater vehicles traditionally belong to one of two types: a large cone-shaped funnel or a pole. By far the most common docking technique is the cone-shaped funnel. In this style of docking station, a large funnel is installed on either the seafloor or any other large system such as on a much larger AUV. The docking procedure for funnel designs involves the AUV homing into the funnel and being guided in by bouncing off of and sliding along the funnel face. Once inside of the funnel, the AUV is latched and power transfer is begun. To undock, the AUV uses reverse thrust until a safe distance away before resuming the mission. Funnel based designs have an excellent capture envelope due to the nature of the funnel shape. They are, however, bulky systems to install and are not adaptable to support multiple types of AUVs.

Pole type docking systems involve a fixed vertical pole with a flat V-shaped latching mechanism on the nose of the AUV. Once latched, the AUV is pushed into the docked position through motorized carriages on the docking station. Pole-based designs enable a large vertical capture area with a relatively small horizontal capture area. Pole docks have historically had problems with homing and maintaining the necessary vertical attitude.

More novel docking solutions have been experimented with including grappling type, stinger and puck, hook, and vertical cones. All of these various solutions each have unique benefits and drawbacks. For example, large funnel shaped docks have a large capture envelope however, the excessive size is a drawback. The small size of the grappling type is desirable, but the capture envelope is very small. An additional consideration in the marine environment (as compared to docking of aerial or space vehicles) is biofouling.

SUMMARY

This summary is intended to introduce, in simplified form, a selection of concepts that are further described in the Detailed Description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. Instead, it is merely presented as a brief overview of the subject matter described and claimed herein.

The embodiments include a system including a docking station, including a flat funnel, and a ramp at a narrow end of the flat funnel and defining a slot and comprising a plurality of inclined planes, each on a respective side of the slot; and a docking adapter, fitted over an underwater vehicle, including a guide plane, and a mast, the flat funnel guiding the mast to the slot of the ramp, and the inclined planes of the ramp guiding the guide plane to a top of the ramp during a docking operation.

The embodiments further include an autonomous underwater vehicle including a hull having mounted therein a rail, said rail having mounted thereon, a buoyancy module mounted forward of the center of gravity of said vehicle, said buoyancy module comprising a ballast tank, which can be cylindrical, of variable volume and a pump, located behind said ballast tank, that adds and removes water from said ballast tank, thereby changing the buoyancy of said vehicle; a pitch module located behind said buoyancy module, said pitch module comprising a mass and an actuator to drive said mass forward and backward with respect to said rail; and a roll module located behind said pitch module, said roll module comprising a servomotor, mounted to said rail, said roll module controlling said vehicle's roll angle and yaw angle by action of said servomotor; a processing module, located between said pitch module and said roll module and being in communication with said roll, pitch, and buoyancy modules, that controls functioning of said roll, pitch, and buoyancy modules; said roll, buoyancy, and pitch modules being mounted concentrically with respect to each other.

