PRESS: OIL & GAS NEWS
August 1, 2017
REMOTELY OPERATED VEHICLES REVIEW
Nova Ray, the subsea remotely operated vehicle (ROV), counters the industry-standard method of overpowering sea currents and pioneers stable submerged movement using a new hydrodynamic shape.
The Nova Ray ROV is designed to be fully responsive and easy to operate in high-current environments having been developed by the Seattle-based Coral Partners.
It has nine patents granted or pending, for both design and utility, a feat which no other submersible ROV has achieved for its entire product. Using its hydrodynamic features to work effectively with the umbilical and the current, as opposed to fighting against those factors, the Nova ray is opposite to nearly all other low cost ROVs. Despite many other manufacturers’ claims, their ROV’s cannot pull the weight of their own cable in a 2-knot current.
The Nova Ray’s patented ‘arcuate’ wing design allows the ROV to be towed successfully while maintaining the option to use thrusters like other submersible ROVs. The Nova Ray has two centers of gravity, which shift seamlessly, under the demands of the operational conditions. The ability to operate under tow and/or thruster power is unique to the Nova Ray.
The basic field unit is also designed with ease of portability and deployment as a priority. The vehicle breaks down into several smaller pieces and can be packed into cases that conform to regular baggage limits for commercial airlines. This allows the vehicle to travel with the operator, thereby increasing response time in emergency situations.
The size of the wing area of the basic Nova Ray ROV allows it to operate successfully (as designed and without modifications) up to 300 meters. The design principles of the Nova Ray are universal and may be applied to larger models for deeper operational capabilities, if desired.
The ROV has a digital communications link between the vehicle and the operator’s console. This digital link eliminates the expansion restrictive radio control systems, which have been prevalent within the industry. The link supports high information transfer rates and is designed to control a diverse mix of on-board subsystems. Due to an on-board computer with proprietary software the vehicle can be flown with a laptop computer from the surface, with the on-board computer eliminating the need for tethered radio control, and creating many options to enhance the performance of the Nova Ray and its physical design.
With its own proprietary software, the Nova Ray is able to incorporate capabilities not seen in most ROVs. Options include a selectable 3-axis auto-pilot control for minor computer navigation assistance, or hands-off control of the vehicle. The operator can have complete control of the system for free range exploring or can choose to configure the vehicle for predefined survey patterns. A heads-up display, NOMAD, developed by Microvision in Bothell, Washington, has been adapted to the vehicle to allow lightweight personal headgear to be worn by the pilot. The headset projects the computer navigation display from the laptop directly onto the retina with a low intensity laser. The lightweight headgear increases the display effectively, while decreasing outside distractions during operations, as well as reducing system transport size and weight.
Selecting computer control for the Nova Ray has demonstrated advantages over radio control. With an on-board computer system, plug and play systems can be designed to augment the vehicle’s tasking characteristics. This allows quick adapt capabilities to perform specialty search, testing and survey work, with mission specific programs already loaded into the computer flight control console. As new capability is developed, existing systems can be upgraded through the integral download port.
When the Nova Ray was designed, hydrodynamic characteristics were given great consideration. The industry standard had been to attempt to overpower ocean current, while simultaneously ignoring the impact of the cable-times-velocity of current on the performance of an ROV or Underwater Towed Vehicle (UTV). The Nova Ray successfully addresses this performance issue and creates barriers to entry.
The Nova Ray wing design eliminates the phenomenon known as “Dutch Roll Instability” a problem experienced by flat wing designs. Anyone who has flown an old fashioned kite and watched it roll side-to-side has experienced this phenomenon. The Nova Ray inventors eliminated “Dutch Roll” by incorporating The ‘arcuate’ form into the wing design. The arcuate-shaped wings of the Nova Ray counteract the lifting force of the cable, therefore the speed of the boat or current will have little effect on the operational stability of the Nova Ray. They not only increased cable efficiency, but have also reduced the amount of cable necessary to operate or tow at depth.
The Nova Ray’s unique hydrodynamic features allow it to operate in a controlled fashion under changing modes. The unique arcuate wing is stable under either tow power or the vehicle’s own thruster power.
Under thruster power, the wing operates just as a high winged airplane would in free flight. Under tow, the arcuate wing, combined with the seamless shift in the center of gravity from the cable pull, produces a stable configuration.
The arcuate wing configuration is remarkably stable in turbulent currents. There is very little tendency for the vehicle to rock in shifting currents. The wing, combined with other secondary control surfaces, tend to counter any destabilizing forces. The close proximity of the thrusters to the control surfaces allows for very tight maneuvering.
None of the Nova Ray’s competitors employ any of these principles in their designs. Competitors basically use “box like” frames and layer them with flotation foam, and then thrusters are added to an already non-hydrodynamic design in order to combat currents and other hydrodynamic forces.
Management of Nova Ray. believes that none of the competition’s ROVs are “truly” towable. While anything can be towed, maintaining reasonable control while being towed is very challenging with traditional ROVs. Management believes that the “box like” vehicles now available in this market segment are not in the same class as the Nova Ray.
[NOTE: factual errors corrected]
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