USA As Represented by Secretary of the Navy

Promode R Bandyopadhyay

Daniel P Thivierge

Alberico Menozzi

James D Hagerty

Anthony B Bruno

Rolf G Kasper

David N Beal

Amuradha Annaswamy

Sahjendra Singh

A small hemispherical drive apparatus actuates the cilia to undergo the limit cycle oscillations. Electromagnets are positioned on a housing of the apparatus. A gimbal with shaft is also attached to the housing. The shaft has a first end within the housing that is proximally separated and remains separated from the electromagnets as the shaft rotates. Generated signals excite electromagnets in sequence to produce an electromagnetic track for the shaft.

Hemispherical drive for autonomic and unconstrained actuation of flapping fins with variable amplitude

A method of depiction of an object in underwater space is provided. The underwater space is acoustically covered using nonlinear wave packets capable of retaining coherence in shallow waters. The echo from the object is encoded as perturbations on flexible cilia-like transducers that are otherwise undergoing limit cycle oscillations. The perturbed pattern of the cilia-like transducers is recorded as holograms and transmitted. The hologram is decoded and a hologram of the underwater space is created. A small hemispherical drive apparatus actuates the cilia to undergo the limit cycle oscillations. Electromagnets are positioned on a housing of the apparatus. A gimbal with shaft is also attached to the housing. The shaft has a first end within the housing that is proximally separated and remains separated from the electromagnets as the shaft rotates. Generated signals excite electromagnets in sequence to produce an electromagnetic track for the shaft.

Acousto-optical method of encoding and visualization of underwater space

An underwater data transmission system including arrays of nano-meter scaled photon emitters and sensors on an outer surface of an underwater platform. For the emitters, a laser is pulsed to correlate with data packets, providing a beam of photons at a prescribed frequency. Nano-scaled collecting lenses channel the incoming photons to photo-receptors located at a focal plane for the frequency at the base of each lens. A coating on the lenses absorbs photons at the frequency that are not aligned with the longitudinal axes of the lenses or tubes. Nano-wires connect the photo-receptors to a light intensity integrator. The integrator integrates the intensity over a surface area. The output of the integrator is fed to a signal processor to track and process the arriving digital packets.

Photo-receptor for electro-magnetic radiation collection

High speed underwater data transmission method

A two-stage voltage step-up converter and energy storage system is utilized for harvesting trickling electrons from benthic microbe habitats. A relatively random low voltage from the microbial fuel cell (less than about 0.8 VDC) is provided to the first stage step-up converter, which stores power in a first output storage device. A first comparator circuit turns on the second stage step-up converter to transfer energy from the first output storage device to a second output storage device. A second comparator circuit intermittently connects the load to the second output storage device. After initial start-up, the system is self-powered utilizing the first and second output devices but may use a battery for the initial start-up, after which an automatic switch can switch the battery out of the circuit.

Power conditioner for microbial fuel cells

Non-linear control laws are disclosed and implemented with a controller and control system for maneuvering an underwater vehicle. The control laws change the phase of one Inferior-Olive (IO) neuron with respect to another IO. One control law is global, that is, the control law works (stable and convergent) for any initial condition. The remaining three control laws are local. The control laws are obtained by applying feedback linearization, while retaining non-linear characteristics. Each control law generates a profile (time history) of the control signal to produce a desired phase difference recognizable by a controller to respond to disturbances and to maneuver an underwater vehicle.

Olivo-cerebellar controller

High-speed underwater data transmission system and method

A system is provided to control maneuvering flapping foils of an underwater vehicle. An oscillator generates periodic signals in which effects of external disturbances are minimized or amplified as required; the periodic signal can be either sinusoidal or can depart significantly from a sinusoid; the amplitude and frequency are varied by changing the oscillator parameters and the phase between the signals are varied by changing the parameters. The oscillator restores the parameters after a disturbance. Since the oscillator functions without external sensors, the oscillator serves as an inner-loop controller with a centralized control. An open loop control architecture for the controller, results in a motion where the vehicle maneuvers execute as force and moment commands. The non-linear, auto-catalytic oscillator can be realized using a variety of second-order differential equations. An oscillator model is added to a conventional motor control, where the outputs of the oscillator control the foils in real-time.

Auto-catalytic oscillators for locomotion of underwater vehicles

A linear actuator is provided that converts linear motion to oscillatory motion. The linear actuator includes flats, a hinge, and linear actuators. A hydrofoil is mountable on a spindle attached to the hinge. In operation, a linear push direction by the linear actuator drive causes the hydrofoil to rotate in an oscillating manner. A linear push by another linear actuator drive reverses the oscillation directions of the hydrofoil. The flats are preferably made of flexible strip metal to easily transmit motion to the spindle. The hydrofoil and spindle combine to a slot for smooth transmission of linear to oscillatory motion.

Linear actuator for flapping hydrofoil

Wake vortices are made less detectable or reduced in their effect on nearby vehicles by re-orientation of vorticity about an axis in the direction of vehicle motion to transverse vorticity interacting with the longitudinal vorticity. The re-orientation may be by a flapping foil, and arrangements of a plurality of foils moving toward or from each other may be used. Alternatively, fluid may be injected longitudinally between opposite surfaces each having a port so that selective suction through the ports alternately attaches the fluid to the surfaces to deflect the fluid from the longitudinal direction and generate transverse vortices. Oppositely rotating vortices may be formed by separators extendable from each surface to engage the deflected fluid, and extension of the separators may be varied to control vortex trajectory. The transverse vortices may be intermittent, selected for speed, or made asymmetric for maneuvering.

Vehicle wake vortex modifier

A wireless power transmission and communication network that provides efficient interrogation and powering of sensors for use on undersea vehicles. The present invention employs a wave-guide that allows the propagation of electromagnetic waves through a dielectric material that covers the exterior of an undersea vehicle's hull. Embedded within the dielectric material is an N dimensional array of Micro Electronic Mechanical Systems sensing devices coupled with radio frequency (RF) decoders and transceivers, and strips of conductive metal tape. Electromagnetic waves such as microwaves propagate through the dielectric material both powering the sensor network and addressing and interrogating individual sensing devices. The sensing devices take readings and then format and transmit the data results back across the wave-guide where they are received and processed by a digital processor within the hull of the undersea vehicle.

Data communication and power transmission system for sensing devices

A wake absorber, wherein an aquatic vehicle with a propulsor mounted on the vehicle and operative to propel the vehicle through a water medium, has a wake absorber mounted on the vehicle aft of the propulsor. The wake absorber includes an artificial muscle surface adapted to be impinged upon by a wake created by the propulsor. The wake absorber further includes electrodes mounted on the artificial muscle surface. Pressure of the wake upon the muscle surface exercises a bending force on the surface, which creates energy that is recovered by the electrodes as electrical power that can be digitized. Energy removed from the muscle surface by the electrodes weakens the wake and renders the wake less pronounced visually and acoustically.

Wake absorber

A polymer ejector system for reducing drag on an external surface of an urwater vessel includes a base portion mounted in an exterior surface of the underwater vessel, the base portion including an arcuate inner wall. A flexible lip portion is positioned above the base portion and spaced apart therefrom. The lip portion has an outer surface substantially coplanar with an outer surface of the underwater vessel, an arcuate inner wall, and is tapered at a distal end of the lip. This lip may be actively moved by means of MEMS deposited electrodes to control the passageway mentioned next. A passageway is formed between and defined by the inner wall of the lip and the inner wall of the base portion, such that the passageway terminates at the outer surface of the underwater vessel and substantially tangent thereto. The ejector may be constructed from single crystal silicon by so called MEMS (Micro-Electro-Mechanical Systems) methods.

Silicon MEMS-based polymer ejector for drag reduction of undersea

A surface layer for use in connection with an object adapted for motion tugh a fluid includes an array of tiles each having a pair of electrodes and a pair of magnetic poles positioned to generate respective electric and magnetic fields generally transverse to each other. Either or both of the electrodes or magnetic poles are controllable to provide adjustable electrical and/or controllable magnetic fields. A plurality of turbulence sensors is provided each located proximate to and generally upstream of a tile. Each turbulence sensor generating a turbulence signal representative of fluid turbulence proximate thereto. A control circuit for controlling the electrical field generated by the electrodes and/or the magnetic field generated by the magnetic pole in relation to the turbulence signal from the turbulence sensors, thereby to generate a Lorentz force for controlling the fluid. The length and time scales of the electro-magnetic tiles can be matched to those of near-wall turbulence in high Reynolds number flows. The tiles can be fabricated using silicon micro-fabrication or printed circuit board techniques, which provides for cost-effective fabrication and ensures relatively lightweight and reduced energy requirements. Due to their smallness, plurality and amenability, digital microprocessor technology with appropriate algorithm maybe used to control near-wall turbulence.

Surface layer comprising micro-fabricated tiles for electromagnetic

An agile water vehicle for travel above and below the water surface, incls a hull having therein a helmsman's compartment, a payload compartment, and a propulsor unit. A rudder assembly is fixed to the hull and includes a cylindrically-shaped (or slightly tapered) tubular member having a rudder thereon and extending therefrom, the tubular member being rotatable. A wing assembly is fixed to and spaced from a bottom portion of the hull, the wing assembly comprising a pair of wings extending widthwise of the axis of the hull, and a flap adapted for disposal in each of the wings and extendible therefrom, the flaps being operable for pivotal movement upwardly and downwardly from the wings. The propulsor unit, the rudder assembly, and the flaps are operable from the helmsman's compartment. A pair of propulsors are disposed on the wings and are rotatable around the spanwise axis of the wings. A pair of differential flaps are mounted on a rotatable axial cylinder or ring with a fixed divider plate therebetween.

Growing community of inventors

Portsmouth, RI, United States of America

Promode R Bandyopadhyay