ABOUT THE AC-ROV

Published: 1st March 2009

AC-CESS and their engineering partners at All Oceans looked at existing small ROV technologies and set to improve upon them.

Principal design drivers were size, mobility, robustness and overall portability. 

The AC-ROV is a full five degrees of freedom underwater video camera and sensor platform. This manoeuvrability is essential as other underwater inspection vehicles do not have the mobility to work in confined spaces.

4 horizontal thrusters operate together to power the AC-ROV forward, back and sideways.  Their “vectored” arrangement is like having 4 forward and 4 side, or lateral thrusters. This is the thruster set up on the vast majority of serious commercial ROVs because lateral power and speed is as important as forward power and speed. One is used to get you to the target, the other is for keeping you face onto the target.  More often than not any current at a target will not be head-on, but SIDE-ON, so serious inspection requires serious lateral flight capability.  This is why the AC-ROV can fly as fast sideways as it can forward and back, or more importantly, hold station in a given current coming from any direction. There are also 2 vertical thrusters for up, down and tilt control.

To make the most of the AC-ROV’s manoeuvrability, the system uses a completely intuitive 3D controller with a single handed grip that can be moved in any direction, rotated and tilted.  The AC-ROV responds by moving in the same way that the grip is moved.  Controlling more movements than any single-handed joystick, it is still easier to use, simply because it doesn’t require brain power. The controller incorporates an array of powerful flight assist functions:

Flight Freeze / Flight Un-freeze / Progressive Forward Flight, Vertical Trim and Tilt / 3 stage Power Increment  / Camera switching.

With a “fly through” size of 190mm and a “drop through” size of 210mm, the AC-ROV can get into seriously small spaces.  The unique AC-ROV thrusters do not have central shafts and the inward pointing blades do not meet. Apart from being very resistant to fouling, they provide full bore equal thrust in both directions.  This is not the case for shaft mounted thrusters which normally have a motor right in the middle of the flow path and a shaft just waiting to foul up. The design results in an overall power to weight ratio 50 -100% greater than other small ROV.   All these market leading attributes are delivered in an extremely robust, reliable, modular design. Its inherent strength and serviceability means that the AC-ROV keeps coming back for more.

SCENARIOS

The AC-ROV is designed for routine inspection, emergency intervention and for those unplanned and non-essential applications which AC-CESS categorise as 'Just Plain Curious'.

Typical applications include:

Propeller, Hull and Rudder Inspections

Hull, Prop or Rudder damage / fowling is the common suspect when ship and boat operators detect abnormal vibration or responses in their propulsion or steering systems. In many countries, even a simple underwater inspection requires the services of a commercially qualified and certified diver. The deployment the AC-ROV is a quick, easy and inexpensive way of determining if there is a problem with underwater parts. If the parts inspect OK, then the cost and time of contracting a diver has been saved. The same saving even applies if a problem is found, because the first manned dive to find out what is wrong is not required, and the actual first dive can proceed with the remedy to hand.

Rapid Response

The key to getting anywhere quickly is availability and portability. Customers buying into the AC-ROV technology take control of the availability issue whilst Portability is one of the greatest benefits of the AC-ROV system. A real 'Hand Carry' system that can be taken just about anywhere. The AC-ROV in one hand, a mini generator in the other and one person can deploy the system in the remotest of locations.

Diver Buddy

A great pre-dive risk assessment and planning tool, making all man dives safer and more productive. Deploy again on diver watch duties. The diver can use the AC-ROV as a 'hand held' or to send on ahead for continuous risk assessment and investigation.  Very useful in confined, congested or poor visibility work environments such as wrecks, culverts, caves and pipes.

Nuclear

Ideal for routine or emergency intervention and inspection in storage ponds, reactors, pipes and ducts.

Homeland Security / Customs and Excise

A portable and versatile tool for routine and emergency remote underwater inspection and intervention. Multiple applications in Ports, Harbours and Waterways surveying ship hulls, bridge piers, jetties etc.

Pressure Vessel Inspection and Certification

Insurance requirements demand that pressure vessels undergo periodic inspection and pressure testing. Water is commonly used to pressure test vessels as it makes the process safer. What better opportunity to deploy an underwater ROV inside the vessel to carry out pre and post pressure test inspections?