Multibody aircrane

• US 20090152391A1
• Filed: 03/02/2007
• Published: 06/18/2009
• Est. Priority Date: 03/04/2006
• Status: Active Grant

• Current Assignee: Bruce Kimberly Mcwhirk
• Original Assignee: Bruce Kimberly Mcwhirk
• Inventors: McWhirk, Bruce Kimberly
• Granted Patent: US 8,157,205 B2
• Time in Patent Office: Days
• US Class Current: 244/30
• CPC Class Codes: B64B 1/02 Non-rigid airships B64B1/58 takes precedence; balloons B64B1/40
• CPC Class Codes: B64B 1/06 Rigid airships; Semi-rigid airships B64B1/58 takes precedence
• CPC Class Codes: B64B 1/70 Ballasting arrangements

Abstract

The MULTIBODY AIRCRANE performs relative positioning, predictive control, and ballast control to achieve very heavy-lifting tasks on land or sea. Such tasks allow station keeping and precise transfer of very heavy payloads between ships underway. This scalable multibody system features three subcomponents: AIRSHIP, SKYCRANE and LOADFRAME. This semi-autonomous system combines aerodynamic (kinetic) and aerostatic (buoyancy force) lift with efficient power and propulsion. During low-speed flight, the Airship and Skycrane are decoupled but linked via a reelable Tether Control Line. Beneath the Skycrane, centered on its hull, a patented NIST (National Institute of Standards and Technology) RoboCrane (featuring a computer controlled six degrees of freedom (DoF) cabling system,) is attached, to precisely suspend and control a Loadframe, with or without payload. During subsonic forward flight, these Airship and Skycrane are coupled as a single airframe (fuselage and delta wing.)

Claims

1. ) Precise Point-to-Point Transfer of Very Heavy Payloads—

This VTOL (Vertical Takeoff &

Lift) air-crane, as an integrated semi-autonomous, stable, inflatable multibody system, contains three distinct subcomponents, an AIRSHIP, SKYCRANE and LOADFRAME, along with a tethered control line system, that during cargo transfer operations, provide active relative positioning, predictive motion control and active ballast control to achieve fast-paced and precise, point-to-point accuracy in transferring very heavy cargoes. When these sub-components are combined to form a single airframe, with fuselage and wing span, this configuration creates aerodynamic (kinetic) and aerostatic (buoyancy force) lift, with more efficient power and propulsion, and a airframe for higher speed subsonic forward flight.

This embodiment incorporates multibody systems dynamics, mobile robotics and tether dynamics to perform a wide variety of very heavy lifting tasks, such as the resupply of ships underway, payload transfer of supplies, heavy equipment and fluids between ships or to or from onshore facilities and other very heavy lifting tasks on land or sea. These very heavy payloads could weigh as much as 200 to 500 tons.

Employing the Multibody Aircrane reduces the “

footprint”

of logistics operations by allowing precise payload pickup or dropoff within a designated target area, such as a cargo deck aboard a ship or even an inland Landing Zone (LZ) located in difficult to reach locations, like tundra, jungles, unimproved or damaged ports, or even in disaster areas.

For at-sea cargo transfer operations, the core issue is the synchronizing or “

tuning”

of relative motions of the AIRSHIP/SKYCRANE and LOADFRAME, the supply ship or containership. Crucial aspects contributing to the multibody system dynamics are the near real-time reactive computations and predictive motions of the Airship and the tethered Skycrane with NIST Robocrane and suspended loadframe (with or without payload).

Air resistance is one of the most important factors in determining the tethered Airship/Skycrane'"'"'s size, stability and propulsive capacity. Although the aerodynamic design of a large lighter-than-air body has a low resistance coefficient, the boundary surface area relevant for air resistance is huge. Frictional resistance, created by currents around an AIRSHIP/SKYCRANE/LOADFRAME is a major factor. For payload transfer operations, air resistance of the entire multibody system can be factored into planned flight path trajectories and can be used to aerodynamically maneuver individual components. For example, air resistance becomes a force for stationkeeping and gliding of the Skycrane with Loadframe above a supply ship in a sea lane and for maintaining safe distances and same relative speed to or from a containership or onshore structure.

When decoupled, the Airship/Skycrane/Loadframe operates at low maximum ceilings over a body of water. Flying at low speeds and low ceiling heights, approximately at mean sea level (MSL), well below pressure height, above cargo ships, conserves helium for reduced operating costs. Wind speeds generally increase as height or altitude increases. A typical wind blowing over water increases, say from 3 knots on the surface, to 4 knots at 7 feet up, and to 5 knots at 15 feet. This increase continues logarithmically up to the top of the “

friction”

layer at 2000-3000 feet.

Altitude adjustment and stationkeeping are kev factors. The AIRSHIP/SKYCRANE can operate over the entire length of a containership, and its NIST ROBOCRANE rigging carrying LOADFRAME with payload can extend or retract to negotiate freeboard (i.e the distance from the oil platform or containership'"'"'s waterline to the upper deck level, measured at the center of the ship) and reach alongside smaller, shallow-hull cargo ships, it therefore offers altitude adjustment for far more agile and efficient cargo transfer operations to or from a Sea Base under varying sea states than deck-base cranes.

This MULTIBODY AIRCRANE addresses a major gap in this Sea Basing concept, namely “

interfacing”

i.e. altitude control and omni-directional maneuvering to negotiate a ship'"'"'s freeboard in order to safely perform the material at-sea transfer of very heavy payloads or tonnage between ships underway in a sea lane. This method of cargo transfer allows for the rapid transfer, formulation or reconstitution of containers or customized cargoes.

Further, this Lighter-than-Air multibody system incorporates both durability and safety by exploiting the impact resiliency of high strength materials and fabrics, along with the natural impact absorption capabilities of inflatable structures.

This embodiment can be applied to almost any ocean-going, heavy lifting tasks where the scope, required heavy-lifting capacity and scheduling necessitates a rapid and efficient operational response. This invention reduces operating time and costs, exposure and investment risk in ocean-going logistics by providing time-sensitive, heavy-lift cargo transfer operations.

The concept of coastal shipping is not new. In fact, Europe is advancing in “

short sea shipping”

after starting initiatives a little more than a decade ago. In Europe today, 40 percent of the freight is moved by water. Additionally, the EU (European Union) has an ambitious “

motorways of the sea”

initiative designed to increase the share of waterborne carriage between EU members. The Europeans have focused on the lower environmental and social costs of waterborne transportation. There, short sea shipping has reduced road congestion, economized fuel consumption, and helped to reduce pollution.

Lifting and transferring 20′

ISO containers via a deck-based crane from and to a giant containership or to smaller Offshore Supply Vessels (OSVs) poses quite heavy dynamic loads due to the energy difference between the internal cargo, the need for boom extensions and the vessel motion with the sea. The top container on a large, fully loaded containership may sit 23.2 m or more above the waterline (not considering wave vertical motion). These operations apply to containerships stacked six or less above the deck. The use of this air-based crane holds several key advantages over the deck-based cranes currently in use or called for in material transfer of cargoes between ships underway at sea. To load, unload and stack containers higher than three levels using an on deck-based crane hydraulic extensions, boom and counterweights have to be adjusted. The rigidness of a deck-based crane is not easily adaptable to vertical motion. Deck-based cranes consequently have tipping, reach and sometimes even bending problems that limit their cargo/weight operational capability at sea. To load, unload and stack containers higher than three levels, ballasting has to be adjusted to a higher level.

The present embodiment has no such constraints, and, even with vertical wave motion, can adjust its operational height (altitude), and carry very heavy loads far across decks or to or from deep cargo holds located over the entire length of the world'"'"'s largest container ship, the Panamax or Post-Panamax class, and could be outfitted to lift and carry up to (6) six 20′

ISO containers at once. The present invention is designed to transfer hundreds of tons of very heavy payload at once between ships underway at sea, cargoes such as large numbers of ISO 20′

containers, fluids (POI, water, etc), or bulk break cargo etc.

2. ) Active Ballast Control—

When a Lighter than Air platform takes on or removes very heavy cargo from a ship underway or offshore oil platform, the critical problem of active ballast control and not valving or venting rare helium when descending is first priority. Helium is too expensive to vent. Solving the critical problem of Active Ballast Control, i.e. managing lift and buoyancy without the need of off-board ballast, and not valving or venting rare helium when descending, entails regulating a forced helium mass flow circulation system to control large volumes of compressed or uncompressed helium. Compressing helium atoms eliminates buoyancy force. Releasing helium atoms in a confined space creates buoyancy force. Therefore, an apt solution to this problem is to transfer a large volume of compressed or uncompressed helium via a forced helium circulation system (featuring high pressure/low pressure pumps, seals, compressors, actuators, and to incorporate advanced lightweight and high strength fabrics and lightweight structures and materials, such as AIRBEAMS) within and between these AIRSHIP and SKYCRANE, for maximum buoyancy, stability, trim and active ballast control.

A primary reason for the MULTIBODY AIRCRANE'"'"'s inflatable architecture and multibody design is to solve the critical problem of Active Ballast Control. Preventing a “

sling shot effect”

when removing payload is a constant danger of lighter-than-air platforms;

At sea, offloading very heavy cargoes from an aircrane with an unsteady reference point onto the decks of a ship in motion only compounds the risk and difficulty. Helium is too expensive to vent and waste. Not having to valve or vent rare helium while at the same time maintaining neutral buoyancy when descending or offloading cargo is a critical problem for airships. Taking on water ballast, the traditional method of ballast control for Airships at such times at sea would be far too time consuming for the rapid transfer or offloading of heavy cargo as required for the MULTIBODY AIRCRANE.

Therefore, an apt solution to this active ballast control problem lies in a new and innovative aerodynamic design approach and fluid dynamics. This multibody system features two interconnected lighter-than-air bodies, AIRSHIP and SKYCRANE, connected by way of a four-way hose system that transfers a high volume of helium via a forced circulation system (with the helium volume having the buoyancy force to offset the payload'"'"'s weight at offloading) way from the Skycrane to the nearby Airship to achieve the Skycrane'"'"'s active ballast control, stability and trim. In turn, the Airship adjusts its own buoyancy and lift by means of both a closed loop helium circulation system and its own internal thermally controlled helium system, i.e. superheating or cooling of the Airship'"'"'s own helium reservoir.

A primary reason for the MULTIBODY AIRCRANE'"'"'s inflatable architecture and multibody design is to solve the critical problem of Active Ballast Control. Preventing a “

sling shot effect”

when removing payload is a constant danger of lighter-than-air platforms.

Active Ballast Control calls for the rapid compression of a large mass of helium. To meet this sizable demand, the Multibody Aircrane employs the following combined and interactive two-fold strategy;

Helium Compression;

Experience has shown that helium compression is highly dependent on power, geometry and mode of confinement. The architecture of the Skycrane'"'"'s internal helium circulation system therefore, becomes a crucial and determining factor in achieving large volume helium compression. When a large mass of helium is pumped under high pressure through a spiral or coiled structure, it can be rapidly compressed (and self-compressed). In this way, localized compression of helium can be achieved in sufficient volume through a very high strength and unique inflated tubular structure;

The Skycrane can rapidly and actively restore torque after offloading a very heavy payload. (This spiral structure has very unique characteristics, including large scale tube-in-tube technology with tubing construction made of special high-strength materials;

Spectra and Polyurethane.) The Skycrane'"'"'s helium circulation system—

in the shape of a spiral, quickly establishes neutral buoyancy at the Skycrane'"'"'s metacenter located above the Center of Gravity (CG) (along the center line running through the spiral).

Integrated Helium Circulation System;

To enhance this spiral circulation structure, a helium filled four-way hose runs between the Airship and Skycrane;

it connects the Skycrane'"'"' helium spiral circulation structure to the Airship'"'"'s own helium circulation system. This reelable four-way hose regulates mass flow and extends to varying hose lengths. To achieve Active Ballast Control, particularly for the Skycrane after payload drop-off, this helium circulation system, linking the Airship and Skycrane, allows for the rapid high pressure buildup or siphons off that high pressure buildup (by sending helium in compressed or uncompressed states through a four-way hose, that runs between these two lifting bodies. Helium in compressed or uncompressed states is pumped in specific volume in either direction as required to introduce mass flow at predetermined times and points. Each hose in the bundle possesses a series of air-tight ports, spaced at different lengths, each port having an ellipsoid shape. This helium circulation system enables a computer software module that anticipates fluid dynamic effects on both the Airship and Skycrane, based on sensors measurements/actuators that actively adjust relative buoyancy forces, stability and trim between the two lifting bodies, based on measured and known local helium'"'"'s pressures, temperatures and volume measurements, and adjustments by high pressure/low pressure pumps, valves and diaphragms, mass flow in the length of polymeric pipes, etc.)

This MULTIBODY AIRCRANE specifically addresses the technical problems associated with ballast, weight, CG, VTOL Balance. Ballast is ‘

enabling’

by providing stability and trim through adjustment of the distribution of mass. Flight simulation accounts for real-world conditions such as extreme weather, fuel shortage, and instrument failures and interoperability with ships. The NASA shuttle is most frequently ballasted to rectify a forward center-of-gravity condition. Propulsive efficiency can be improved by reducing the amount of ballast carried, but practical considerations, such as the stability in roll. In accepting reduced, or even negative, stability margins some aircraft achieve weight reduction, but artificial stability, in the form of active controls, must be introduced. Ballasting can be avoided in many cases by good weights management. In this design, compressed helium and superheated helium are keys to solving the ballasting problem. Advanced structural technologies, reliance on computerized components, electronic chips safety and automation technologies are keys to AIRSHIP/SKYCRANE'"'"'s affordability, effectiveness, and less risk.

For Active Motion Control to work, it is necessary to realize that a large percentage of the loadframe and payload motion is dependent upon the containership'"'"'s heading. Employing the AIRSHIP/SKYCRANE with vertical lifting capability allows both it and a containership or cargo ship underway at steerage speed to conduct cargo transfer operations with a heading chosen to minimize roll. During underway vertical resupply operations, the supply vessel or containership below experiences wave action to its stern, (i.e. it sails in a following sea.) Employing the AIRSHIP/SKYCRANE allows a ship underway at steerage speed to conduct cargo transfer operations with a heading chosen to minimize roll. The ship'"'"'s heading and forward speed are dominant factors in determination of a ship'"'"'s heave, pitch and roll. Large vertical motions occur more in head seas in excess of 6 knots or lower than in following seas of the same rate. Relative vertical motion of 2.0 meters or more occurs in head seas or in following seas in excess of 6 knots, regardless of the mechanical conditions.

3. ) Loadframe as a “

Soft Landing Mechanism”

—

Still another object is to employ a modular loadframe as a “

soft-landing mechanism.”

This tubular, truss-framed, open-bottomed, rectangular box is suspended from the SKYCRANE via a NIST ROBOCRANE, contains an internal pneumatic system used to transport, pick up and discharge ISO containers. “

The “

Soft Land Mechanism”

Loadframe”

—

constitutes a rigid, lightweight, high-strength, rectangular, open-ended box (constructed of composite tubing), with an air pump and rapid air-inflated pneumatic system featuring interior piping and external pressurized POLYURETHANE pods—

high strength inflatable balloons—

that surround, stabilize and cushion the payload. This Loadframe lands its payload of up to six containers at the ship'"'"'s target area, simultaneously decompresses and retracts its pods and releases the payload (via a high strength, quick-release, mechanical cable and winch system located at the loadframe'"'"'s base) to achieve fast-paced payload delivery performance (or, in the reverse, a pick up). Acting as a load suspension stabilizer and container protector, this rigidized Loadframe reduces the time required to safely and efficiently load-on/load-off payloads of up to 6 (six) ISO 20′

containers at once. For load-off operations, the Loadframe is suspended and slipped over the stack of six containers, stabilized by an air inflatable balloon system, winched by cables to the bottom container nearest the deck, and picked up. For load-on operations, the process is reversed. This loadframe/soft landing mechanism is designed to operate across the entire shipboard cargo area. It improves logistical operations and efficiency of shipboard conveyers, container shuttle mechanisms, forklifts, rolling equipment, ramps and elevators etc. Still another object of this “

Soft Landing Mechanism”

Loadframe is to make the MULTIBODY AIRCRANE capable of reaching, delivering and retrieving heavy payloads from cells deep inside the largest container ships currently afloat (Panamax or Post-Panamax class ships), along with current or proposed Navy Sea-based ships such as a 90,000-ton MPF(F) or a high-speed containership (a 55,000-ton Panamax beam ship., etc.) This Loadframe provides easy access and reach to decks and holds by being suspended from a cabling system (NIST RoboCrane) for rapid container stacking and transfer on fully laden containerships. Operations would apply to container ships stacked six levels above the deck.

Internal handling of cargo containers or pallets and vehicles requires automation. Rapid, flexible logistics supply will likely require tailored packages from a robust selective offload system. Requirements for cargo types and throughput rates assumes cargo comes on board as ISO containers or pallet sized loads. Still another object is of the “

patent pending”

design is to incorporate a modular “

Soft-Landing Mechanism”

with Loadframe and air-pressurized pneumatic system to act as a load suspension stabilizer and container protector, thus reducing time required to safely and efficiently load-on/load-off payloads of up to 6 (six) ISO 20′

containers at a pre-selected target area. But this Loadframe/soft landing mechanism would be designed to operate across the entire shipboard cargo area.

The AIRSHIP/SKYCRANE is designed to operate over the entire length and freeboard of a containership, along its main deck and deep into its holds. The throughput rate of these transfers of course depends upon such conditions as sea states, all multibody speeds and headings, distancing of ships in a sea lane (with or without fenders), size of ships, and targeting and weight of payload for load on and load offs (LO/LO) on decks or deep in holds, etc. But by using this invention, throughput rates could be as high as 795 tons per hour.

This Multibody Aircrane addresses a number of current operational problems found at sea in deck-based cranes and heavy lift vehicles, such as rotorcraft or quad tilt rotor designs, engaged in the in-air material transfer of very heavy payloads, including;

Stability (Hydrostatics);

The design'"'"'s # 1 issue is dynamics. An excellent control system and a sufficient power supply is required for moving large masses around quickly. When moving such large structures, a problem arises;

stability (hydrostatics). If two or more components of this multibody system begin moving to the beats of different drummers, the entire structure could easily be severely damaged. One solution to the problem is to design in added rigidity, but that adds weight, which can significantly increase cost. Consequently, the embodied Airship and Skycrane system, structure, envelope design, and drag coefficients, with flow values for such subsonic structures with high Reynolds numbers, are maximized for stability and trim. The shapes of these bodies are curvilinear to achieve “

soft”

contours for aerodynamic performance, efficient boundary-layer air flow, and to minimum turbulence. In a sense, the stabilization problem divides into its two components,

     1) the forces on the craft resulting from lifting the load, and

     2) the forces acting on the craft, whether during stable flight, hovering or maneuvering. Also, at very low speeds, like any buoyant vehicle, aerodynamic controls for an airship do not work at all and control reversal, i.e. a non-minimum phase behavior, is quite a reality.

Therefore the interaction of the AIRSHIP and SKYCRANE and LOADFRAME with ships underway at sea requires slower speeds increases operational safety. But offshore transfer and lifting of heavy cargo and logistics packages from an SKYCRANE and suspended LOADFRAME to a ship at sea or oil platform imposes quite heavy dynamic loads on the tethered “

sling”

or LOADFRAME due to the energy difference between the cargo and the vessel moving with the sea. Lack of stability and equilibrium can result.

This embodiment incorporates advanced science and technologies relating to Aeronautics &

Aerodynamics, Multibody Systems Dynamics, Mobile Robotics, Tether Dynamics, a “

Fly by Wire”

computer-controlled avionics system, state-of-the-art power and propulsion systems, and advanced materials including high-strength fabrics, composites and polymers. This air-crane also incorporates WiMax broadband wireless technology. With this AIRSHIP/SKYCRANE/LOADFRAME the virtual mass is just as important as the actual mass. With the present embodiment, these problems of size, weight and power are solved. Responding and adapting to external, dynamic real-world forces throughout the multibody system requires adjusting for oscillations excited by clear-air turbulence, wind gusts, crosswinds, prevailing winds, undulating wave heights, tidal shifts, abrupt weather changes, maneuvering, heavy weight shifts and shifting Center of Gravity (CG) and Metacentric Height (GM), air-crane or ship sudden maneuvers, and winding up the cables are principal design points.

Still another object of the embodiment is to incorporate a mobile robotics system that relies on the principles of multibody systems dynamics, incorporating a virtual simulator, distributed software with three-layer software architecture (like NASA'"'"'s Atlantis software system) for intra-system monitorings activation/deactivation and network control and flight trajectory monitoring and control. Kinematics and Multibody Systems Dynamics develops mathematical procedures, or “

formulations”

, that automatically generate the equations of motion for complex systems such as the tethered, large flexible bodies within this Multibody Aircrane, given only a description of the system as input. By encoding these formulations into computer algorithms, powerful computer-aided tools for dynamic analysis are created. Multibody System Dynamics is characterized by algorithms or formalisms, respectively, ready for computer implementation. The simulation of this multibody systems demands adequate dynamic models that take into account various real-world phenomena, along with nonlinear effects that appear as a result of the action of each component within this multibody systems, as well as their mutual interaction. The virtual prototyping and dynamic modeling of all components in the Multibody Aircrane systems is developed and integrated for (Containership, Loadframe, etc.) and flexible bodies (AIRSHIP, SKYCRANE, Tether Control Line) that performing spatial motion and various complex tasks. As a result simulation and animation featuring virtual reality are developed. Virtual prototyping of these up-to-date objects and their actions in this multibody dynamics system allow for standardization of data, coupling with CAD systems, parameter identification, real-time animation, contact and impact problems, extension to electronic and mechatronic systems, optimal system design, strength analysis and interaction with fluids. Furthermore, the integration of real-time measurements derived from sensors result in a reduction of time and methods for the rigorous treatment of simple models and special integration codes for Ordinary Differential Equation (ODE) and Differential Algebraic Equation (DAE) representations support numerical efficiency. Newly developed software engineering packages with modular approaches improve the efficiency of prediction of vehicle dynamics in this mobile robotics system.

Still another object of this AIRSHIP/SKYCRANE/Loadframe is to incorporate a auto-pilot “

Fly by Wire”

IT Flight Control System and Mobile Robotics architecture to maximize network integration and distributive tasks for flight trajectory planning and controllability. a robust guidance and control system is required, capable of auto-piloting and controlling the multibody configuration under an extremely wide range of atmospheric and wind conditions.

The software architecture consists of a 3-layer structure, combined with a high-level data flow programming method and system development environment. The Semi-Autonomous IT Flight Control System and Mobile Robotics software is integrated by a such as WiMax (area-wide broadband wireless communications) network and internal and external SENSORS (such as LADAR, Doppler Radar, DGPS, along with a digital camera capable of Visual Servoing for Navigation and Payload transfer target identification) and ACTUATORS to implement precise targeting and flight path determination with mobile robotics control, target identification and navigation, adjustable lifting speeds at altitudes within close proximity of the ship'"'"'s deck facilities, (yet within safe range and height ceiling to avoid collisions and conduct safe payload transfer operations between ships underway at sea, while avoiding each ship'"'"'s superstructure and all shipboard obstacles.

Precise Station-keeping &

Motion Compensation—

Stationkeeping or the problem of local “

persistence”

of the AIRSHIP/SKYCRANE and LOADFRAME ((maintaining speed and adjustable altitude relative to underway ship(s) or target area below) requires precise control and maneuver of all bodies within the multibody system, creates a principal design point. Transferring and lifting of very heavy cargo and modules by the Skycrane to or from ships at sea or offshore oil rigs imposes quite heavy dynamic loads on the tethered loadframe due to the energy difference between the internal cargo and the vessel moving with the sea.

Precise stationkeeping allows better area airspace coordination for flights of other air platforms such as onboard rotorcraft (MV-22 Osprey or CH53E) and even protecting fixed wing aircraft during cargo transfer operations at the Sea Base. Fundamentally, precise stationkeeping prevents collisions with ship'"'"'s superstructure, flight decks, stacked containers, etc.

A key objective of this Lighter-Than-Air crane system is to reduce the power and fuel supply requirements for forward flight and very heavy cargo transfer between ships underway at sea or very heavy lifting in at sea projects. Reducing power and fuel consumption increases the AIRSHIP/SKYCRANE'"'"'s “

persistence”

, i.e. the amount of time that the air-crane can remain on station and perform very heavy lift operations.

Especially intended for performance of heavy lift cargo transfer operations at sea, this lighter-than air configuration is not a giant airship in the traditional sense. Instead, this VTOL aircrane employs multibody system dynamics with three distinct subcomponents, AIRSHIP and SKYCRANE and LOADFRAME. By dividing the essential functions—

power and propulsion, maneuver, and payload lifting into smaller, more discrete, mutually supporting, manageable, and controllable sub-units, (along with introducing tethers and rigging and elongating the air-crane'"'"'s shape), this VTOL aircrane'"'"'s physical size of is more easily managed in headwinds and crosswinds, each subcomponent'"'"'s aerodynamic features (as a function of each components Reynolds numbers and boundary layers) are made more flexible and maneuverable, air resistance is reduced as a countervailing force, the risk of collision with a ship'"'"'s superstructure or deck is lessened, and each flight control for each component, when combined with propulsion and active ballast control, is made more precise to complete the task of point to point transfer of very heavy payload.

Oscillations Control—

The integration and use of advanced smart materials/structural components, sensors/actuators and advanced computer programs are integrated throughout the multibody system to provide appropriate active stiffness and dampening of oscillations by responding and adapting to external, dynamic real-world forces When controlled hovering over a body of water is called for in conditions of high wind or high sea states, these airships tend to become unmanageable due to air cushioning effects and venturi reactions. The multibody system must adjust for oscillations excited by clear-air turbulence, wind gusts, crosswinds, prevailing winds, undulating wave heights, tidal shifts, abrupt weather changes, maneuvering, heavy weight shifts and shifting Center of Gravity (CG) and Metacentric Height (GM). Windloads, airship maneuvers, and winding Up the cables can create oscillations. Therefore measures for damping these oscillations actively and passively requires applying methods of nonlinear dynamics. The numerical analysis of mathematical models for the Airship Skycrane/load frame oscillating would be developed. Such a program seeks to address grappling/docking/friction issues by accommodating large lateral reference points and planer alignment, along with tether control line angle and tensile strength and torque between AIRSHIP and SKYCRANE, physical distancing between these bodies and LOADFRAME (with or without cargo) distancing from the SHIP. These factors need to be known to determine the volume of compressed HE needed and any HE transfer, AIRSHIP/SKYCRANE, LOADFRAME power and propulsion requirements, all are methods to accommodate and correct large lateral and angular misalignments. Wind speeds generally increase as height or altitude increases, effecting the interaction at low elevation of

AIRSHIP/SKYCRANE/LOADFRAME as well as this air platform'"'"'s interaction with surface vessels. Because winds effects surface wave action, cargo transfer operations will be effected within the proposed Sea Base'"'"'s Vessel Windage Area, particularly in Sea State 3 through 6. The virtual values and numbers for wind conditions must approximate real-world conditions with physical changes in various parts of the globe, along with local temperature, humidity, atmospheric pressure, sea states, wave heights, sea breezes (a seaward/landward convection wind in coastal zones in altitudes of less than 3000 feet that rarely exceeds a velocity from 10 to 20 knots) etc.

To withstand the extreme forces and stresses incurred during high and low speed flight, advanced materials for envelopes, particularly high strength fabrics, such as SPECTRA (10×

stronger than steel) for the Airship and VECTRAN (5×

stronger than steel) for the Skycrane, have the tensile strength needed for such durable and stiff envelope designs. The unprecedented use of lightweight and ultra-strong Airbeams that are high pressure air-inflated fabric tubes made of VECTRAN (5×

stronger than steel) incorporated throughout the entire multibody'"'"'s geometry insures tensile supports with appropriate structural stiffness and stability. Another strategy is to incorporate, where appropriate, advanced lightweight and very high-strength fabrics materials like the elastomer POLYURETHANE, along with new lighter-truss structures such as AIRBEAMS) within and between these two lighter-than-air bodies, the AIRSHIP and SKYCRANE, for maximum buoyancy, stability, trim and lift management.

For these subcomponents, the progressive decrease in physical size—

from AIRSHIP to SKYCRANE to LOADFRAME (with or without payload)—

when combined with innovative lift strategies and propulsion systems for each, gives the overall multibody system approach for better air resistance/drag management, for enhanced flight control, maneuverability and operational flexibility. Thus this Multibody Aircrane configuration achieves more responsive, timelier, and precise point to point transfer of very heavy cargoes. Precise Control/Maneuverability of this Loadframe near and on a ship'"'"'s deck and superstructure and over the water'"'"'s surface also reduces loitering time to achieve speedier and more precise point to point transfer of very heavy cargoes between ships underway at sea. Also, the progressively reduction in physical size of each component increases safety by limiting the risk of collision with the ship'"'"'s superstructure, cargo deck (with radar, antennas, onboard cargo, cranes, equipment, vehicles, and crew, etc.) or even other aircraft flying within the overall operational zone.

The SKYCRANE incorporates NIST'"'"'s RoboCrane technology featuring adjustable and suspended computerized rigging and platform (attached above and onto the LOADFRAME) for maneuvering with six degrees of freedom (DoF), to manage close-in positioning and refine oscillation control and stationkeeping of the Loadframe/“

Soft-Landing mechanism.”

Utilizing an adjustable ballasting system, lift-on or lift-off (Lo/Lo) cargo transfer operations under random Sea States 3, 4+ in higher velocity winds over a body of water can safely and efficiently be performed.

Vertical Lift-on/Lift-Off (LO/LO);

According to recent studies by NIST—

National Institute of Standards and Technology—

Intelligent Systems Division and Structures Division, Bethesda, Md., oscillations of a container suspended from a deck-based crane greater than 1.4 m (4 ft) with relative speeds of up to 0.3 mps are large enough in relative motion to pose a safety risk and cause damage to a containership. The same conditions hold for the embodied Multibody Aircrane. When a “

sling”

of cargo approaches the vessel'"'"'s deck, its lifting speed must be higher than the maximum vertical speed of the waves. The reason is obvious, since the vessel may collide with the cargo if the lifting speed is too small. To avoid the possibility of a lifted container'"'"'s impact with the deck or a cargo on deck of ship'"'"'s superstructure, the crane must have enough power to rapidly compensate the relative motion between the crane'"'"'s lifting apparatus and the container. The relative motion is determined by comparing two points in space by actively measuring speeds with Doppler radar, distance with Laser scanner (LADAR) technology for measurement distances. Power and propulsion and actuator adjustments are then determined. It is safe to conclude, however, that the smaller the relative motions, the less demanding the operation will be for the crane, both in technology, and in power. The power for lifting a container at a desired speed after the container is lifted off the deck may be more demanding than that required for the motion compensation at the moment of pickup.

Still another object of this embodiment is to minimize interference with stacked containers and flight deck operations and to extend the Multibody Aircrane'"'"'s reach deep into a containership'"'"'s holds.

Still another object of this embodiment is (when necessary) to employ a hook and sling or suspended platform capable of lifting a mix of containers, break bulk cargo, vehicles, fluids, barge sections and even smaller pallet-sized loads to or from smaller ships. In high sea states, wave motion compensation would have to be more robust and faster, especially for smaller ships. Under more extreme weather conditions, smaller vessels have greater relative motion than larger vessels, like containerships. Under these circumstances the Multibody Aircrane may employ a hook and sling.

Still another object of this embodiment is to incorporate an adaptable crane mechanism with a hook capable of lifting disabled roll on/roll off (RO/RO) vehicles from ramps.

Interoperability with Large and Smaller Ships;

An air-based crane allows for more precise targeting of payload, and its ballasting and transfer to a ship. This method protects a cargo ship'"'"'s stability and trim, especially for a smaller vessel (like an Offshore Supply Vessel (OSV)), that is more susceptible to heave, pitch, and roll in high Sea States. During, cargo transfer operations with the embodied air-based crane, the transfer of a single payload of 200 to 500 tons, for example, would likely have little effect on the stability and trim of a Post Panamax containership, whereas a payload transfers of say 70 to 100 tons to a smaller ships would have much greater effect. If ftilly loaded or light loaded, in calm or turbulent seas, a containership'"'"'s stability and trim can be more accurately predicted and safely adjusted for by computing;

Displacement

KG (Center of Gravity)

GM (Metacentric Height)—

The characteristic of a ship which helps determines its stability in the water.

An underway ship impacted by external forces basically behaves as a pendulum of length GM. The value of GM is determined by a large number of factors, including a vessel'"'"'s length-beam ratio, underwater cross-sectional profile, waterplane coefficient, bilge and keel shape, the placement of specific weights (which determines the location of the KG center of gravity), the amount of freeboard, and others.

RA (Righting Arm)—

As weight is added to a vessel (either deliberately through periodic updating or conversion, or inadvertently as a result of flooding from battle damage) this situation will tend to reduce the ship'"'"'s design RA curve (the plot of the magnitude of righting moment) which is considered to be the best indicator of stability.

The standard relationship is basically;

Larger metacentric height (GM)=larger Righting Arm (RA)=greater stability

Longitudinal Center of Gravity (LCG)

Transverse Center of Gravity (TCG)

Calculative Drafts

Navigational Drafts

Sizing up wind conditions in the immediate vicinity is important, but even more important is recognizing wind change ahead of time, particularly local wind variation rather than major shifts due to frontal passages. Sensors may be employed to accomplish this task. For example, Professor James L. Garrison of Purdue'"'"'s Aeronautics and Astronautics Department has conducted recent research using the GPS signal itself as a remote sensing instrument. While at NASA, he demonstrated that the spatial correlation properties of the GPS signal, after reflecting from the ocean surface, can be inverted to retrieve information about that surface to make meteorological measurements (wind speed and direction). Another new technique for measuring wind speed in advance is to employ LIDAR, a instrument that measures by Laser. Scientists working a NASA'"'"'s Mars Lander project recently developed the so-called “

Enhanced-Mode Ladar,”

an optical air-speed sensor to be used as a meteorological wind-speed sensor for a Mars lander. This sensor has been developed for aircraft use to replace the familiar, pressure-based Pitot probe. Their approach utilizes a new concept in the laser-based optical measurement of air velocity (the Enhanced-Mode Ladar), that allows the LADAR to make velocity measurements with significantly lower laser power than conventional methods.

In reference to surface wind speed at sea, one may consult the U.S. Navy'"'"'s definition for sea states found in NATO STANAG 4194. Standardized Wave and Wind Environments and Shipboard Reporting of Sea Conditions. Particular attention may be paid to understanding the “

standard deviation”

of direction for wind traces or each wind type. The ultimate size of the seas depends upon the strength of the local wind and the length of the fetch, the area of the ocean affected by the wind. Roughness of the sea is directly dependent on the velocity of the wind and its fetch.

Strong winds blow over the open ocean. But these winds are weaker at the surface of the ocean (because of friction with the water.) A wind of less than 15 knots, to pick an arbitrary number, would be of little concern in the proposed cargo transfer operations. The maximum wave that a 10-knot wind can generate is 2 feet in height. And this would be with a very long fetch. These waves will usually be much smaller. Actually, locally generated wind wave heights can be estimated from fetch distance measurements.

On the water'"'"'s surface, local wind velocity is determined by whether the air is stable or unstable. The question of the air'"'"'s stability depends on the vertical temperature distribution aloft. It is normal for temperature to decrease with altitude at a rate of about 3 degrees per thousand feet. If the air cools upward more rapidly than this rate, it is unstable. If the air temperature increases aloft, as it does for short stretches, the air is stable. In other words, warm air over cold is a stable condition. Cold air over warm is unstable. The reason, of course, is that cold air is heavier and tends to sink. However, if the lower layer is cold, with warm air above, only stable horizontal currents result. Below 3000 feet winds are “

gusty”

, with less speed because of surface friction (wind currents are stronger above this altitude because of the elimination of this drag effect.) Surface winds gusts are simply reflections of “

batches”

that have plunged to Earth. Gustiness is greater during daytime than night because normal nighttime cooling gives the surface a protective layer of cool air, allowing the gradient wind to slide over the top. The sea breeze, the convection current the flows back and forth along the coast from landward to seaward, within a band of 30 miles, when assigned a direction, is generally a stable wind.

The ship'"'"'s heading and forward speed are dominant factors in determination of a ship'"'"'s heave, pitch and roll. Large vertical motions occur more in head seas in excess of 6 knots or lower than in following seas of the same rate. The relative motion of 2.0 meters or more occurs in head seas or following seas in excess of 6 knots, regardless of the mechanical conditions. For Active Motion Control to work, it is necessary to realize that a large percentage of the container motion is dependent upon the containership'"'"'s heading. For optimum performance in underway replenishment, and greatest stability, the containership should sail in a sea lane with winds to the stern in following seas of 6 knots or lower.

Speed Requirements;

The MULTIBODY AIRCRANE'"'"'s propulsion system must meet these exacting speed parameters. During forward flight when the Airship and Skycrane are coupled together, the Multibody Aircrane must attain relatively high speed to move quickly over long distances. When coupled together as an airframe, the system operates at higher speeds (<

500 mph) to fly across water and across greater distances to arrive at a sea base or inland terminal. Conversely, during cargo transfer operations, when the Airship and Skycrane are decoupled and operating within, to or from a Sea Base, these components must be able to maintain high and low speeds especially to rendezvous and interoperate with ships sailing at up to 40-70 knots in a sea lane. To maintain controllability of these tethered components at these high and low speeds, therefore, is major point in this MULTIBODY AIRCRANE design.

Also, at moderate to high speeds, it is the aerodynamic forces that contribute most to a platform'"'"'s motion. Aerodynamic control surfaces like rudders and elevators are attached to the empennage surfaces. Deflection of the former controls the yaw movements (going to the left or right) whereas the latter controls the vehicle'"'"'s altitude (going up or down). Air jet thrusters help adjust relative position, stability and trim.

To address this power and thrust problem, the most appropriate solution to employ turbofans. Introducing jet technology to a lighter-than-air multibody system poses challenges to stability and trim and requires aerodynamic airfoil designs with envelope materials capable of sufficient structural strength and rigidity to withstand the forces and stress incurred during high and low speed flight. Advanced materials, particularly high strength fabrics for envelopes, such as Spectra for the AIRSHIP and Vectran for the Skycrane, have the modulus and tensile strength needed for such durable and stiff envelope designs.

Of all the world'"'"'s most robust heavy lift air platforms none can employ mobile robotics to slowly maneuver, perform loitering and station-keeping and VTOL to accomplish very heavy lifting feats (in excess of 20 ton cargoes) on a ship'"'"'s deck-based target area—

neither fixed wing aircraft such as the Antonov An-225 Mriya (dream), the world'"'"'s largest airplane with a maximum payload (internal) of 220.5 tons, Galaxy C-5A nor C130 nor heavylift rotorcraft such as Mil Mi 26 or CH53E nor an advanced hybrid quad-tilt rotor V-22 Osprey. Greater Throughput Capacity of Heavier Tonnage and Operational Reach;

This heavy lift, lighter-than-air system provides faster, precise point to point transfer and or delivery of very heavy cargoes from ship to ship or from ship to shore for improved supply chain management. Currently no air platform in the world can accomplish the primary task of lifting 200+ tons at sea. A Lighter-Than-Air very heavy lift air-crane is the only practical design exclusively configured to transfer very heavy payload at sea (200+ tons) between ships underway (under shipboard conditions of speeds up to 50+ knots and Sea States 3+).