Abstract: A small aperture acoustic velocity sensor and a method for velocity measurement are disclosed. In one aspect, the disclosed technology uses spatially-shifted sub-arrays for projection and/or hydrophone receipt and cross-correlation of successive pulses to improve correlation and reduce bias. The spatial shift can be created physically by selection of groups of elements or virtually by weighting the contributions of fixed sub-arrays. Spatial modulation can be used to form a projected signal and measured spatial phase of slope across the set of sub-arrays allows correction of both long- and short-term errors. The disclosed technology uses spatial and/or temporal interpolation.

Abstract: An acoustic dual-frequency phased array system with common beam angles is disclosed. In one aspect, the system includes a planar array of transducer elements and a multiplexing circuit for selecting between a first state and a second state during either transmit operation, receive operation or both transmit and receive operation. The multiplexer is configured to connect transducer elements to a plurality of connections different between the first state and second state. The system is configured to transmit and receive beams at a first frequency when the multiplexer is in the first state and transmit and receive beams at a second frequency when the multiplexer is in the second state. The angle of the beams from vertical in the first and second state are substantially similar.

Abstract: An underwater active sonar system and method for measuring instrument velocity with respect to a boundary surface is disclosed. The system includes an acoustic transducer configured to transmit and receive a plurality of acoustic beams in different directions. The system also includes a processor configured to detect a boundary surface within each beam; iteratively filter received acoustic signals backscattered from the transmitted beams with an adaptive filter and associated bandwidth that is successively decreased for each iteration; and measure instrument velocity with respect to the boundary surface.

Abstract: A redundant memory for use with an instrument arranged to acquire and store data while underwater. Such an instrument comprises a main housing which contains instrument electronics that acquires and may process data received from one or more sensors, with a primary memory located within the main housing and arranged to store at least some of the acquired and/or processed data, and a secondary memory which stores a copy of the data stored in the primary memory. The instrumentation may be arranged to write data to the primary and secondary memories contemporaneously in either a burst or continuous mode, or with primary memory backed up to secondary memory periodically and/or in response to the occurrence of a triggering event. The instrument may comprise a second housing within which the secondary memory is located. The main and second housings may be contained within a common enclosure.

Abstract: An acoustic transducer and method of generating acoustic transmit and receive beams is disclosed. The system includes a plurality of transducer elements arranged to form an array, where the elements are electrically connected into groups which operate at the same electrical phase, where the phases of adjacent groups of elements differ by between about 50 and 70 degrees and a beamforming circuit where the transmit and receive signals are operated with appropriate phase shifts to maintain the between about 50 and 70 degrees phase difference between adjacent groups. The resulting transducer generates transmit and receive beams that are nominally inclined less than about 30 degrees from a planar normal axis of the array.

Abstract: A connector comprising a contact, a plunger, and a spring activated seal is provided. The contact is positioned within the housing and configured to transmit at least one of an electrical signal and an optical signal between the connector and a secondary device. The plunger is positioned within the housing and in communication with the contact. The spring activated seal comprises a flexible portion and a spring configured to urge the flexible portion to contact the housing and at least one of the plunger and a contact of the secondary device to form a fluid tight seal therebetween.

Abstract: A connector comprising a contact, a plunger, and a spring activated seal is provided. The contact is positioned within the housing and configured to transmit at least one of an electrical signal and an optical signal between the connector and a secondary device. The plunger is positioned within the housing and in communication with the contact. The spring activated seal comprises a flexible portion and a spring configured to urge the flexible portion to contact the housing and at least one of the plunger and a contact of the secondary device to form a fluid tight seal therebetween.

Abstract: A submersible sound system may include a housing, an end piece, an elastic membrane, an end cap affixed to the elastic membrane, and a subwoofer speaker system disposed within the housing and supported by a speaker support. A bubble sound source may be defined by the speaker support, the speaker diaphragm, an anterior end of the housing, the elastic membrane, and the end cap. The housing, end piece, and a posterior surface of the speaker support may form a sealed enclosure. The sound system may include a tuning pipe disposed between the sealed enclosure and the bubble sound source. A Helmholtz resonator may be disposed anteriorly of the speaker system. Multiple sound system may be assembled to form a cluster. The cluster may be defined by the vertices of regular polyhedron. The sound systems may be controlled to maintain the speaker systems within acceptable thermal limits.

Abstract: A small aperture acoustic velocity sensor and a method for velocity measurement are disclosed. In one aspect, the disclosed technology uses spatially-shifted sub-arrays for projection and/or hydrophone receipt and cross-correlation of successive pulses to improve correlation and reduce bias. The spatial shift can be created physically by selection of groups of elements or virtually by weighting the contributions of fixed sub-arrays. Spatial modulation can be used to form a projected signal and measured spatial phase of slope across the set of sub-arrays allows correction of both long- and short-term errors. The disclosed technology uses spatial and/or temporal interpolation.

Abstract: Messages on controller area network (CAN) buses are communicated over subsea links. Messages are sent as electrical or optical signals. The present invention provides a subsea CAN BUS electronic distribution unit (EDU) for transmitting, receiving, converting, and routing electrical or optical signals sent over a subsea CAN BUS network. The CAN BUS EDU of the present invention is contained within a single housing and combines the functions of transmitting, receiving, converting, and routing electrical or optical signals sent over a subsea CAN BUS network that would typically be handled by multiple devices.

Abstract: The present invention provides a modular electrical feedthrough system for use in offshore and top-side electrical submersible pump (“ESP”) installations. A modular electrical connection system includes a stab receptacle assembly for mating with a stab plug assembly and a compliance mount. The stab plug assembly includes stab plugs and guide funnels adapted to guide the stab receptacles into a mating position with the stab plugs. The compliance mount compensates for physical misalignment between stab receptacles and stab plugs. A tubing hanger assembly forms a pressure barrier at a production bore by use of a tubing hanger penetrator assembly including a set of seals to isolate the electrical penetrator from the production bore. A secondary penetrator assembly provides a redundant pressure barrier for increased safety and system reliability.

Abstract: A hybrid energy harvesting system for powering underwater vehicles having at least one thermal engine, at least one of a solar or a wave energy harvester, and a battery which stores electric energy produced by the harvesters. The energy harvesters keep the battery charged and thereby expand an underwater vehicle's operational areas to high latitudes and shallow water. Multiple thermal engines employing different phase-change materials can be used to expand the vehicle's working temperature range and thus allow it to operate over a larger area. An electric motor powered by the battery and a pump driven by the motor can be used to pump hydraulic fluid between the accumulators and external bladders of the thermal engines to cause the vehicle to descend and ascend when the thermal gradient to which the vehicle is subjected is insufficient.

Abstract: The present invention provides a system for providing a stress reduction apparatus for a ceramic electrical penetrator or pin in a subsea environment. More specifically, the present invention provides a deformable translatable seat in an annular pocket that prevents the transfer of shear forces from a shell or fixture to a ceramic electrical penetrator or pin. The present invention provides a relatively soft metal seat that conforms to the profile of the shoulder of a mating electrical penetrator or pin and deforms to reduce or eliminate concentrated bearing stresses. The deformable translatable seat may also shift and deform within the annular pocket to relieve shearing stresses exerted on the electrical penetrator or pin by the shell or fixture.

Abstract: The present invention relates to a robotically manipulatable wet-mateable subsea connection system suitable for use in harsh subsea environments. The robotically manipulatable wet-mateable subsea connection system of the present invention comprises a bulkhead receptacle unit, a flying lead plug unit, and a removable, reusable, robotically manipulatable connection tool.

Abstract: The present invention provides a system and method for providing a seal for an electrical penetrator in a subsea environment. More specifically, the present invention provides for a system for creating a seal about an electrical penetrator without using o-rings or independent seals. The present invention provides for a set of supporting apparatuses to be placed in compression about a central ceramic penetrator element. The geometry of the central ceramic penetrator element and the interior of the supporting apparatuses forms a hermetic seal when under a constant radial and axial, or axial compressive force.

Abstract: The present invention provides a system for providing a stress reduction apparatus for a ceramic electrical penetrator or pin in a subsea environment. More specifically, the present invention provides a deformable translatable seat in an annular pocket that prevents the transfer of shear forces from a shell or fixture to a ceramic electrical penetrator or pin. The present invention provides a relatively soft metal seat that conforms to the profile of the shoulder of a mating electrical penetrator or pin and deforms to reduce or eliminate concentrated bearing stresses. The deformable translatable seat may also shift and deform within the annular pocket to relieve shearing stresses exerted on the electrical penetrator or pin by the shell or fixture.

Abstract: The present invention relates to a robotically manipulatable wet-mateable subsea connection system suitable for use in harsh subsea environments. The robotically manipulatable wet-mateable subsea connection system of the present invention comprises a bulkhead receptacle unit, a flying lead plug unit, and a removable, reusable, robotically manipulatable connection tool.

Abstract: Messages on controller area network (CAN) buses are communicated over subsea links to subsea devices that also require electrical power to function. These subsea devices may be disposed kilometers away from the signal source where electrical signal and power transmission is impractical. The present invention provides a subsea power-over-fiber CAN bus converter for converting CAN bus electrical input and electrical power input into optical signals for transmission over a fiber optic cable for conversion into CAN bus electrical output and electrical power output for use by a subsea sensor or other subsea device. The subsea power-over-fiber CAN bus converter of the present invention is may comprise a flying lead harness that has a first connector end, a second connector end, a first optical converter module, a second optical converter module, and a fiber optic cable disposed between the first and second optical converter modules.

Abstract: Messages on controller area network (CAN) buses are communicated over subsea links to subsea devices that also require electrical power to function. These subsea devices may be disposed kilometers away from the signal source where electrical signal and power transmission is impractical. The present invention provides a subsea power-over-fiber CAN bus converter for converting CAN bus electrical input and electrical power input into optical signals for transmission over a fiber optic cable for conversion into CAN bus electrical output and electrical power output for use by a subsea sensor or other subsea device. The subsea power-over-fiber CAN bus converter of the present invention is may comprise a flying lead harness that has a first connector end, a second connector end, a first optical converter module, a second optical converter module, and a fiber optic cable disposed between the first and second optical converter modules.

Abstract: Messages on controller area network (CAN) buses are communicated over subsea links. Messages are sent as electrical or optical signals. The present invention provides a subsea CAN BUS electronic distribution unit (EDU) for transmitting, receiving, converting, and routing electrical or optical signals sent over a subsea CAN BUS network. The CAN BUS EDU of the present invention is contained within a single housing and combines the functions of transmitting, receiving, converting, and routing electrical or optical signals sent over a subsea CAN BUS network that would typically be handled by multiple devices.