Autonomous Draft Determination

Navy SBIR 21.1 - Topic N211-076
NAVSEA - Naval Sea Systems Command
Opens: January 14, 2021 - Closes: February 24, 2021 March 4, 2021 (12:00pm est)

N211-076 TITLE: Autonomous Draft Determination

RT&L FOCUS AREA(S): Autonomy

TECHNOLOGY AREA(S): Sensors

OBJECTIVE: Develop a concept for an autonomous or unmanned method to determine a vessel�s draft accurately (Objective 1/16"; Goal 1/8") during required naval architectural experiments in various weather conditions with various hull forms to support on-time delivery of ships and submarines.

DESCRIPTION: Naval architectural experiments (i.e., inclining experiment and displacement check) are conducted prior to ship delivery to the fleet; avoiding schedule delays of these experiments by removing the small boat portion prevents delays of on-time delivery. The existing method can be hazardous and requires a manned small boat to collect draft readings at four locations (port and starboard; bow and stern) using a draft tube. Draft readings with draft tubes rely on personnel judgment due to reading the meniscus in the equipment that is not standardized between shipyards and may result in inconsistencies in draft readings taken. As much as practicable, the system developed should be used by shipyards to standardize the process of taking draft readings during naval architectural experiments. The system developed should be more efficient with at least a 50% reduction in time and/or labor (reduced schedule risk and reduced labor and travel costs), accurate (Objective 1/16"; Goal 1/8"), safer, and completely autonomous method to determine the draft of a vessel when conducting naval architectural experiments. The system should reduce schedule risk to on-time delivery and reduce costs associated with these experiments. The system developed will require fewer people (less cost) for the experiment, reduce risk of experiment delay due to the weather conditions that prohibit the small boat from going in the water to measure drafts (could mean up to ~100 people wasting 8 hours waiting for weather and ~20 people staying an extra night to perform the experiment the next day), and shorten the duration of the process in its entirety. The system should be operable in various weather conditions, including several feet of chop on the water surface and wind; and be able to determine draft on various hull forms including flared (e.g., carrier) or tumble homed (e.g., submarine) hulls and draft marks. Draft marks have a projected height of six inches but can be longer on the hull depending on the hull�s curvature. This SBIR topic will contribute to reducing life-cycle costs (these experiments are performed throughout a vessel�s life) while leveraging technology and data analytics. Observation of the draft marks and water surface could be recorded and the video could be converted to data to perform statistical analysis to obtain the average draft while the water surface perturbates. The existing method relies on personnel judgment to average out the perturbations and record an average reading, which is not objective, repeatable or standardized. Additionally, an autonomous system will allow the data collected to be stored and analyzed later whereas with the existing method, the reading is taken and a photograph is taken but they are difficult to verify or analyze later due to the angle of the photograph, lighting conditions, and timing of the photograph with wave action. These experiments require the vessel to be nearly complete and occur within days or weeks of delivery so any delays in accomplishing these experiments can impact on-time delivery of ships and submarines. There are approximately 20-25 experiments per year across the submarine fleet and 10-15 experiments per year across surface ships and aircraft carriers. These experiments are necessary to ensure the stability and safety of US Navy ships and submarines, are required by NAVSEA, and are applicable to submarines, surface ships, and aircraft carriers. The technological solution would likely be a device that the shipyards (both public and private) would procure. Utilizing an autonomous method to determine the draft of a vessel would reduce the set-up time and equipment needed, streamlining the process and reducing cost and schedule risk, and would not put personnel at risk (personnel have fallen into cold water and have almost been crushed between boat and pier).

PHASE I: Develop a concept for reading draft marks to sufficient accuracy (as stated in the Description) on submarines and surface ships during naval architectural experiments. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.

PHASE II: Develop a prototype based on Phase I work for demonstration and validation. Demonstrate the operation of the prototype to read draft marks with various hull forms and various weather conditions to sufficient accuracy as stated in the Description. The new system will be compared to results obtained using the traditional method by shadowing an experiment with the new system and/or using the ghost fleet in Philadelphia or a barge since they may provide easier access than an active Navy shipyard with commissioned boats. Deliver the tested device and associated software at the end of Phase II.

The prospective contractor may require access to U.S. shipyards (public and/or private) or other U.S. Naval facilities to demonstrate the capability. The system likely includes software so the software would have to meet applicable Navy requirements (e.g., IA, cyber, COTS).

PHASE III DUAL USE APPLICATIONS: Assist the Navy to integrate the Phase II-developed device and software into standard operating procedures at the shipyards and standards at NAVSEA for Fleet-wide use on submarines, surface ships and aircraft carriers.

The commercial shipping industry also performs inclining experiments to meet U.S. Coast Guard and/or classification society standards so U.S. or foreign shipyards may be interested in this device.

REFERENCES:

  1. Tsujii, Takahiro; Yoshida, Hiromi and Iiguni, Youji. "Automatic draft reading based on image processing." Optical Engineering, 55(10), 14 October 2016. https://www.spiedigitallibrary.org/journals/optical-engineering/volume-55/issue-10/104104/Automatic-draft-reading-based-on-image- processing/10.1117/1.OE.55.10.104104.full?SSO=1
  2. Hirono, Kouhei; Sera, Wataru; Fuchi, M. and Kinzo, Inoue. "A Theoretical Study of the Draft Reading Device." The Journal of Japan Institute of Navigation, March 2006. https://www.researchgate.net/publication/312351203_A_Theoretical_Study_of_the_Draft_Reading_Device
  3. Powers, Earl. "Development and Use of a Tool to Accurately Measure Freeboards." SNAME, SMC-2019-55. https://www.onepetro.org/conference-paper/SNAME-SMC-2019-055
  4. "Are Drones the Future of Marine Surveying?" Martek Marine, 9 Jun 2017. https://www.martek-marine.com/blog/are-drones-the-future-of-marine-surveying/

KEYWORDS: Navigational draft; draft marks; inclining experiment; displacement check; draft reading; draft analysis software.

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