Exploring the ocean is an important task that humanity needs to solve, but we cannot rely only with the fragile human body to search in the dangerous depths of the sea. That is why we needed a device to help us exploring the vast and deep oceans.Remotely Operated Vehicles (ROVs) represent a significant advancement in underwater technology, offering a versatile solution for exploration, inspection, and intervention in aquatic environments. An ROV is essentially an unmanned, highly maneuverable underwater robot that is connected to a surface vessel via a tether. This tether allows for real-time control and data transmission, enabling operators to explore ocean depths without being in the water. While using ROVs eliminates the “human presence” in the water, in most cases, ROV operations are simpler and safer to conduct than any type of occupied-submersible or diving operation because operators can stay safe (and dry!) on ship decks. ROVs allow us to investigate areas that are too deep for humans to safely dive themselves, and ROVs can stay underwater much longer than a human diver, expanding the time available for exploration.
Underwater ROVs (Remotely Operated Vehicles) are advanced submersible robotic systems designed to explore and observe the depths of large bodies of water. Operated remotely from shore or by divers, these vehicles provide a safe and efficient means of accessing underwater environments for inspection, research, and exploration. ROVs come in various sizes, from compact models as small as a basketball to larger units comparable to an SUV. Their prices range widely, starting at a few thousand dollars and reaching several million dollars for larger, advanced systems.
Main Components:
- Frame : The frame of the ROV provides a firm platform for mounting, or attaching, the necessary mechanical, electrical, and propulsion components. This includes special tooling/instruments such as sonar, cameras, lighting, manipulator, scientific sensor, and sampling equipment. ROV frames have been made of materials ranging from plastic composites to aluminum tubing. In general, the materials used are chosen to give the maximum strength with the minimum weight. Since weight has to be offset with buoyancy, this is critical.
- Propulsion systems : ROV propulsion systems come in three different types: Electrical, hydraulic, and ducted jet propulsion. These different types have been developed to suit the size of vehicle and anticipated type of work. In some cases, the actual location of the work task has dictated the type of propulsion used.
- Power source : On a surface-powered ROV system, power arrives to the vehicle from a surface power source. The power can be in any form from basic shore power (e.g. 110 VAC 60 Hz or 220 VAC 50 Hz ” which is standard for most consumer electrical power delivery worldwide) to a DC battery source.
- Electric motor : Electric motors come in many shapes, sizes, and technologies, each designed for different functions. By far the most common thruster motor on observation-class ROV systems is the DC motor, due to its power, availability, variety, reliability, and ease of interface.
- Cable Tether : Cable Tether functions as a tether to the main vessel, and is also used as a signal transmitter for the ROV to give real time video image of the underwater landscape
- Camera : Main device used to record and give real time footages of the underwater landscape
How ROV Work
These underwater machines are controlled by a person typically on a surface vessel, controlled with a joystick or a controller, like you are playing a video game. A group of cables connects the ROV with the vessel that sends electrical signals back and forth.
Most ROVs are equipped with at least a still camera, video camera, and lights, meaning that they can transit images and video back to the ship. Additional equipment, such as a manipulator or cutting arm, water samplers, and instruments that measure parameters like water clarity and temperature, may also be added to vehicles to allow for sample collection.
First developed for industrial purposes, such as internal and external inspections of underwater pipelines and the structural testing of offshore platforms, ROVs are now used for many applications, many of them scientific. They have proven extremely valuable in ocean exploration and are also used for educational programs at aquaria and to link to scientific expeditions live via the Internet.
ROV strengths and weaknesses
Strengths:
- Quick Deployment: Due to its compact design and easy to use inspection technology, underwater ROVs can be deployed in a moment’s notice.
- Minimal Maintenance: Underwater ROVs are robust and rugged in design, built to withstand harsh water environments, and require minimal maintenance. Typically, ROVs can last years without the need for major repairs.
- Personnel Safety: ROVs offer a safer alternative for exploring hazardous underwater environments. Whether operated from shore or alongside divers in the water, they can access dangerous areas to gather data or recover materials, reducing the need for divers to be exposed to risky conditions.
- Cost-Effective Solution: Compared to larger submersibles, micro ROVs offer a significantly more cost-efficient alternative. Ideal for exploring narrow underwater areas, capturing high-quality footage, and collecting data, micro ROVs provide an affordable solution without compromising on performance.
Weaknesses
- Dangerous on deployment : Potentially dangerous situations are inherent during all stages of ROV operations. During launch and recovery, deck crew and ROV engineers are on the back deck of the ship assisting with operations. In rough weather (i.e., wind over ~25 knots or 29 miles per hour and waves over ~6 feet), the ship’s movvements could become so extreme that the deck crew could lose their footing on deck, or the ROVs could swing unsafely while being lifted by the crane.
- There is no specific formula : There is no precise formula that we can use to decide whether or not it is safe to dive. When preparing for a deepwater ROV dive, the navigator, dive supervisor, and ship operators study the three major forces acting on the ship.
