The disclosure of the present patent application relates to boating apparatus, and particularly to an autonomous hull biofouling cleaning system for autonomous or semiautonomous removal of biofouling from the hull of a boat or ship while the vessel is still afloat.
Biofouling, also known as biological fouling, is the accumulation of bacteria, plants, and algae on dampened surfaces causing structural or functional concerns. It's an undesirable collection of various aquatic organisms on maritime ships, and it will immediately impact any surface immersed in seawater. In general, fouling occurs substantially more rapidly in warm waters. There is a more considerable risk of fouling whenever ships spend long periods either idling or sailing at lower speeds. Besides, it is observed that biofouling accumulated at the discharge openings of the power plants and the nuclear stations would block the water flow and causes serious consequences.
A thick fouling layer can accumulate on the hull, significantly increasing friction against the water with considerable financial and environmental impacts. According to the International Maritime Organization (IMO), biofouling accounts for approximately 9% of all fuel consumed by ships, with an annual expense of around USD30 billion. Furthermore, biofouling accelerates the deterioration of the affected structures or surfaces, which causes increasing operational costs. Biofouling is associated with severe environmental issues. Overconsumption of fuel releases greenhouse gases, which harm the environment, resulting in the unnecessary release of 80-90 million metric tons of CO2. However, emissions are not the only factor to consider. Hull biofouling also poses a substantial bio-security risk to marine ecosystems by spreading invasive aquatic species. And according to IMO, ship bio-fouling has a further negative impact on the entrance of invasive aquatic species than untreated ballast water.
The process of dry docking a boat or ship to clean the hull with land-based equipment is time-consuming, expensive, and labor-intensive, and removes the boat or ship from service during the process. Although some apparatus have been proposed for cleaning biofouling from the hull of boats and ships have been proposed, there is still a need for a system to remove biofouling from the hull of a vessel while it is afloat that is operable autonomously or semi-autonomously. Thus, an autonomous hull biofouling cleaning system solving the aforementioned problems is desired.
The autonomous hull biofouling cleaning system includes a floating platform mounted on pontoons and having thrusters to move the platform close to a hull needing cleaning. The floating platform includes both axial and transverse sliding ballast to prevent the platform from overturning from the collection of debris. Mounted on the platform is a solar power apparatus for providing power to the various modules, a motorized hose reel, concentric hoses mounted on the reel, an ozone pumping apparatus, a vacuum debris collection apparatus, and modules for sanitizing the debris to return sanitized water to the body of water. A submersible remotely operating cleaning system (SROCS) is attached to the hose and includes thrusters to move adjacent to the hull, electromagnetic coils to attach to the hull, and rubbing discs to remove the biofouling, the hose first pumping ozone on the biofouling and the vacuum debris hose removing the biofouling to the floating platform for processing.
These and other features of the present subject matter will become readily apparent upon further review of the following specification and drawings.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
The autonomous hull biofouling cleaning system includes a floating platform mounted on pontoons and having thrusters to move the platform close to a hull needing cleaning. The floating platform includes both axial and transverse sliding ballast to prevent the platform from overturning from the collection of debris. Mounted on the platform is a solar power apparatus for providing power to the various modules, a motorized hose reel, concentric hoses mounted on the reel, an ozone pumping apparatus, a vacuum debris collection apparatus, and modules for sanitizing the debris to return sanitized water to the body of water. A submersible remotely operating cleaning system (SROCS) is attached to the hose and includes thrusters to move adjacent to the hull, electromagnetic coils to attach to the hull, and rubbing discs to remove the biofouling, the hose first pumping ozone on the biofouling and the vacuum debris hose removing the biofouling to the floating platform for processing.
Some features of the system include the hollow shape of the floating cylinders equipped with an axial Balancing mechanism for the right and the left side floating cylinders that includes a sliding cylindrical balancing weight connected with either an axial screw connected at one end with the motor to move the cylindrical balancing weight axially forward and backward based on the balancing requirements, or link to any axial mechanism like steel cable to perform the same axial motion. The cylindrical balancing weight contains smooth sliding bearing balls to reduce friction with the inner walls of the floating cylinders.
A stabilization actuation mechanism engages during operation to keep the floating platform stable and prevent it from flipping, as well as to protect the conveying system from damage. The mechanism responds to external disturbances that affect platform stability, particularly when sand and debris accumulate in the collection box, causing unbalanced impact, or when waves occur.
The system uses a motorized reel that holds a double wall hose, in which the inner pipe is connected to an ozonizer to feed ozone while cleaning the biofouling to eliminate and disinfect any trace of the removed biofouling, and the outer tube is connected to a vacuum system for sucking the eliminated biofouling and to transport it with seawater to the filter station. The beginning of the hose at the reel base is split into two split pipes, one goes to the ozonizer, and the other one goes to the vacuum station. The front side of the double hose is connected to the SROCS system. A two-way supply hose is connected to the SROCS from one side, and on the other side to a motorized reel system to supply and pull the hose during SROCS movement. It consists of an inner hose for supplying ozone from the platform to SROCS through a 12V DC air pump and an outer hose that that is connected to the vacuum extraction module for collecting the extracted biofouling and debris.
The structure of the floating system has two chassis, one connecting the floating cylinders, and the other is the main deck platform. The two chassis are sliding across each other through the sliding bracket for the aim of energy harvesting to create a relative motion.
The floating cylinders are hollow and can be split into two halves and connected by bolts and nuts for the maintenance, assembly, and disassembly process. The floating cylinders are hollow from the inside and can be injected with foam. Ballast can be attached to the lower half of the floating cylinder to perform the lower center of gravity of the system. The modular system has multiple hollow floating cylinders that are cascaded together by pipes sleeves and can be extended in the longitudinal and transverse directions. Floating cylinders can be shaped in a transverse direction for double, triple, and more columns, and connected by the system chassis to increase system payload capacity.
A sliding ballast resides inside the pipe sleeve and can be moved forward and backward via a controlled actuation mechanism fixed at one of the ends to balance the system's center of gravity and thus prevent flipping. The main control system controls the mechanism based on real-time feedback from the floating platform level sensor. A real-time closed-loop feedback control system is used to control the position of the sliding ballast based on the real-time actual floating platform level to maintain the system balance, especially when sand and debris are accumulate in the sand collection box, causing an unbalanced impact. The sliding ballast is surrounded by bearing balls to maintain smooth motion. The ballast can be extended by adding more weights through connected joints. Besides the axial balancing mechanism, the system has a transverse balancing mechanism at the front and the back of the platform, attached to the floating chassis that is made of a sliding bracket. The ballast has a curved shape to match the floating cylinder profile.
The Submersible Remotely Operated Cleaning System (SROCS) is an autonomous underwater robot equipped with an advanced motion control unit that enables the robot's orientation in the XYZ plane to be controlled. A nine-axis Inertial measurement unit (IMU) that consists of an accelerometer, gyroscope, and magnetometer to detect rotation in three-dimensional space is included.
An ultrasound sensor measures the distance between the SROCS and the hull surface, and when it reaches the surface, electromagnetic coils are excited to mount the SROCS on the surface, the thrusters are turned off, the cleaning process begins, and the motorized wheels move forward and backward.
A set of motorized main and secondary rubbing discs rotate to remove biofouling and debris from the ship's exterior. Debris and biofouling are guided to the center of the main disc, where the vacuum extraction module (VEM) will suck them up. SROCS includes the following modules: (1) an Advanced Motion Controller (AMC), which receives orientation in the XYZ plane and relative position to hull surface information from the navigation and surface inspection module and commands the four thrusters to achieve the desired position and orientation. The AMC excites the mounting electromagnetic coils and operates the cleaning discs and the motorized wheels, also commanding the motorized hose reel. (2) A Navigation and Surface Inspection Module (NSIM) that communicates in real time orientation in the XYZ plane and relative position with respect to the hull surface to the AMC. (3) An Electromagnetic surface Mounting Module (ESMM) holds SROCS on the Hull surface during the cleaning process. (4) A Biofouling Elimination Module (BEM) that has motorized rubbing discs that rotate to achieve the cleaning.
Multiple platforms can be synchronized and commanded to achieve the cleaning of larger ships and surfaces. A ground station can command multiple systems to work together using loT technology over a satellite communication channel. Each station is transmitting its current location using a GPS navigation module. The ground station processes this information and sends positioning commands to each platform to prevent collision.
The system has two energy harvesting mechanisms, the first being the axial electromagnetic sliding strips that are mounted in the floating structure chassis and the body chassis. The harvesting process takes place whenever there is a relative motion between the two chassis due to water waves. The second harvesting mechanism is the linear electromagnetic actuators mounted between the system's transverse chassis, where the base is fixed at the floating chassis, and the harvesting head is fixed at the sliding body chassis.
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An ultrasound sensor measures the distance between the SROCS 24 and the hull surface 127, and when it reaches the surface, electromagnetic coils 105 are excited to mount the SROCS 24 on the hull surface 127, the thrusters 107, 108, 109, 110 are turned off, the cleaning process begins, and the motorized wheels 106 move forward and backward.
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The second energy harvesting mechanism is the linear electromagnetic actuators (LEA) 119, 120 mounted between the system's transverse chassis, where the base 121 is fixed at the floating chassis 34, and the energy harvesting head 122 is fixed at the sliding body chassis 113.
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The platform-mounted modules 46 include the motorized reel system 52 for paying out and reeling in the hose 22 as needed, and an ozone sanitation module 54 having an ozonizer and air pump assembly for pumping ozone onto the biofouling as needed. A vacuum extraction module 56 provides for collecting biofouling debris mixed with seawater on the floating platform 12, where it is first processed by a UV sanitation module 58 providing irradiation by UV light at frequencies killing harmful biological organisms in the debris and seawater, and then by a biological filtering module 60 for removing particulate matter and discharging the cleaned seawater back into the body of water.
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Thus, the autonomous hull biofouling cleaning system 10 provides a complete and efficient system for autonomous or semi-autonomous cleaning of biofouling from the hulls of waterborne vessels.
It is to be understood that the autonomous hull biofouling cleaning system is not limited to the specific embodiments described above, but encompasses any and all embodiments within the scope of the generic language of the following claims enabled by the embodiments described herein, or otherwise shown in the drawings or described above in terms sufficient to enable one of ordinary skill in the art to make and use the claimed subject matter.
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Cybernetix Magnetic Hull Crawler (MHC); downloaded on Mar. 7, 2023. |
Fleet Cleaner Robot; printed on Mar. 7, 2023. |
AOS Offshore Magnetic Hull Crawler; downloaded on Mar. 7, 2023. |
SeaRobotics HullBUG; printed on Mar. 7, 2023. |