This lesson introduces you to the VideoRay Defender system providing basic information about the vehicle and topside components. Additional lessons will present an overview of the software and operational activities from set up and basic controls through strategies and tactics for complex and demanding missions.

The VideoRay Defender is an extremely powerful and capable ROV (Remotely Operated Vehicle) that uses an umbilical tether and is operated from the surface. It supports a number of sensors and tools enabling it to perform a wide variety of underwater tasks and missions. The control software is state-of-the-art and when the vehicle is equipped with appropriate sensors, the system is capable of autonomous operations.

The base Defender vehicle includes a high definition camera, high intensity LED lights, and an AHRS module that provides information about the ROV’s attitude, including the heading, depth, pitch and roll . It uses 4 thrusters for horizontal movements including lateral motion and 3 thrusters for vertical motion, attitude control and heavy lifting. Additional vehicle accessories are available and will be described later.

The OCC (Operator Control Console) includes a built in computer and a 19” high definition display, topside Ethernet and USB ports, and the ROV power and communications interfaces. Missions can be recorded on the computer's hard drive and distributed by using a flash drive or over the Internet. An external power source is required, but the system can also be powered by a generator or batteries.

The control software is provided by Greensea Systems, a world leader in autonomous vehicle control software. The intuitive and autonomous software makes it easy for novice pilots to navigate the vehicle to where it needs to be and reduces sensory and task overload for all pilots. Additional lessons will describe the software and its features and capabilities in more detail.

The VideoRay Defender can be used with VideoRay’s IP65 hand controller or Microsoft’s Xbox Elite gamepad style controller. The hand controller allows the operator to navigate the vehicle manually and control various functions like tilting the camera or changing the light intensity. Additional controller styles can be configured to work with the system.

As mentioned, the vehicle is tethered to the surface using an umbilical cable. The umbilical can be used in a manner similar to extension cords. Each umbilical has a male connector and a female connector and you can connect multiple tethers together. This capability makes it easy to optimally configure the equipment for shallow or deep dives. The Defender can use standard copper umbilical or for long deployment lengths, hybrid fiber umbilical is available.

While the VideoRay Defender is a powerful and nimble ROV, sensors and tools turn it into a workhorse, capable of operating effectively in murky water and performing search and recoveries, inspections and various other manipulation tasks. Accessories are optional, but the Defender can be equipped with accessories installed and configured when purchased.

The TDS (Tether Deployment System) makes it easier to manage longer tether lengths.

The Blueprint Subsea Oculus M750d and M1200d are dual frequency multibeam sonars that can be used for navigation and identification. Each sonar includes a low frequency for longer range and a higher frequency for better resolution and image quality. The Defender pitch control can be used to aim the beam at the bottom ahead of the vehicle or looking upward when inspecting a ship’s hull or underside of a floating pier.

The Inuktun Rotating Manipulator includes 5 different sets of jaws, including a cutter. The jaws can be rotated a full 360 degrees. On the Defender, the manipulator is mounted on a dual position track so that it can be extended straight ahead or angled 30 degrees downward. Vehicle pitch adds even more angular control for hard to reach places. The manipulator is held in the retracted position by two screws – one on each side near the back of the manipulator. It is spring loaded, so resistance to extending should be applied when removing the screws. The screws can be completely removed or reinserted after the manipulator has been extended.

The VideoRay ROV GPS can be used to "seed" the world position of the ROV. The GPS antenna / module is mounted on an retractable mast. The mast should be extended for operations and retracted for land transport and storage. It can be extended and retracted by pulling or pushing on the module. It has click-in stops at each end of travel. GPS does not work underwater, but as you will see, other sensors can be used to track the location of the vehicle once it submerges.

The Topside GPS can be used to determine the georeferenced location of the control station when operating from a moving vessel. It can also be used during stationary deployments to provide a visual reference of the operating location on a map.

The Nortek DVL (Doppler Velocity Log) is an acoustic location tracking device. When coupled with AHRS data of heading, depth and attitude, it provides a complete navigation system that not only pinpoints the location of the vehicle, but tracks its movement across the bottom. The navigation solution can be used to enable dynamic positioning, or station keeping, maintaining the position of the vehicle without pilot intervention, even in current. The navigation solution also allows the pilot to command the vehicle to navigate autonomously to a specific position, such as a sonar target for closer inspection, or through a series of waypoints that define a course. Defining a search pattern for covering large areas without fear of gaps is easy. The DVL bottom tracking range is limited to about 75 meters (or 250 feet) of altitude above the bottom.

The Blueprint Subsea Seatrac USBL, or Ultra Short Baseline System, is another acoustic position tracking device. The operating principle uses a topside transducer beacon at a known location and a vehicle transducer beacon that responds to “pings” from the topside. The system interprets the phase shift of the returning “ping” within the sensor head and calculates the position of the ROV. This system can be used in conjunction with the DVL to fill the gap between the surface and the 75 meters (or 250 feet) limit of the DVL when working in deeper water.

Some important Defender specifications to be aware of include the vehicle depth rating of up to 1 km (or 3,280 ft). The standard float block (yellow top cover) is only rated to 400 m (or 1,300 ft), but a deeper rated float block is available. Most accessories are rated to 300 m (or 1,000 ft), but some accessories can be ordered with a deeper rating.

The Defender system requires an external power source and uses a universal power supply input of 100-240 V AC, 50,60 Hz. Power can be supplied by a land based grid, generator or batteries.

The Defender Vehicle weighs 17.2 kg (or 38 pounds). It has a forward speed of 4 Knots and Bollard Pull of 23.5 kg (or 52 pounds) (almost 1.4 times the vehicle weight. It is capable of lifting 11.3 kg (or 25 pounds) and with pitch control can maintain level attitude and full navigational control while carrying that weight.