Artificial Fish: AUVs Designed to Model Animals
Humans venture beneath the ocean's surface to collect resources, conduct research, engage in warfare, and perform countless other tasks. The need for increasingly specialized technology to accomplish these tasks has prompted the development of many different designs of submersibles, varying from manned nuclear submarines to Remotely Operated Vehicles (ROVs) dragged behind surface ships, to untethered Autonomous Undersea Vehicles (AUVs) (Blidberg 1). This last design, the AUV, has received special attention in recent years as humans explore greater and greater depths. As its name suggests, the AUV functions independently, without intervention from a human operator. It carries its own power source (traditionally a battery), and receives all its commands from an onboard computer, thus involving some degree of artificial intelligence. This computer serves to direct the robotic submersible in performing a pre-defined task. Because its movement is not restricted by a cable connecting it to a mother ship, the AUV is ideal for operating in hazardous areas and at great depths. Current and proposed activities for AUVs include undersea exploration, scientific sampling of physical oceanic conditions (such as salinity level and temperature), laying and inspection of gas lines and cables, searching for downed aircraft, and mine reconnaissance (Canfield, Hylands).
A key aspect of common AUV design, however, prevents this list of activities from expanding and limit the current potential of AUV performance. Due to the inefficiency of propulsion and power systems, AUVs are highly unstable in any turbulent water, are limited to short missions, can carry only small payloads, and have little maneuvering control at low speeds (MIT, Canfield). In the most unfavorable of conditions, AUVs may not even be able to reach their intended destinations while traveling at slow speeds, despite the use of slow speed guidance systems (Healey 335). Small rotary propellers plagued with low efficiency and lagged response times typically power AUVs (MIT). Furthermore, batteries often require 70% of the hull space (MIT). Closely tied to efficiency of propulsion systems is the hydrodynamic shape of the submersible's hull. While hull designs have improved over time, they do not compare to the hydrodynamic efficiency of fish and aquatic mammal shapes. As Jeff Walker, a biology professor at the University of Southern Maine, stated, "It's a lofty goal for a human-made vehicle to achieve the performance of a fish" (qtd.
The Korean People’s Navy has a large inventory of well equipped submarine ranging from attack subs to midget type subs. Attack subs have improved sonar, and capable of carry 14 torpedoes or 28 mines. While the midget type subs are used for clandestine operation with the Special Operation forces.
Personal Watercrafts or "jet skis" are basically Personal Watercraft (PWC) are basically small inboard boats able to travel at high speeds due to large amounts of power and very light weight. Alomst all PWC's are under 600 lbs and most of todays PWC's have at least 90 hp.Not only are PWC's some of the fastest water vehicles they are also some of the most maneuverable water vehicles. This is because PWC's propultion is based on a jet that also is it's turning mechanism. When the driver turns the handlebars the jet (via cables) turns in the direction of the handlebars so the stern is pushed in the opposite direction. This allows the driver to turn at a much tighter angle than traditional boats with keels and rudders.The main drawback to this maneuverability is the fact that if there is no thrust coming from the engine the ability to turn is effictively zero meaning that anytime the driver presses the kill switch (a large red button) they lose all ability to steer. This is extremely dangerous whenever an inexperienced person may drive the PWC back to dock or into shore. PWC's have no brakes and have no ablilty to stop other than turning around. They have an extremely efficient ability to hydroplane (when most of the PWC is above water) and it takes most PWC's a few hundred feet to come to a stop after being at full throttle. This is because 600 lbs + a rider is traveling at a very high speed with only minimal friction to slow them down (since PWC's are made to travel with very little friction).
Biomechanics is the overall topic that will be discussed throughout the presentation, this incorporates a brief discussion about water resistance, propulsion and buoyancy. Under lifesaving, appropriate techniques and the choice of stroke for the Timed Tow will be analyzed and justified.
In Blackfish, Director, Gabriela Cowperthwaite, addresses the accidents that occurred at SeaWorld involving trainers and whales. Cowperthwaite’s purpose is to educate the audience on the cruel treatment and rough conditions of whales that occur in SeaWorld. The film maintains a shocking tone in order to persuade the audience and appeal to feelings of sadness and anger.
Archaeology is a continuously evolving field where there is a constant stream of new branches and excavation methods. Due to the influx of new technologies and innovations in recent decades, archaeologists have been able to excavate previously inaccessible areas. For example, new diving equipment and tools such as proton magnetometers, side-scan sonar, sub-bottom profiler, and miniature submarines have allowed archaeologists to dive into the deep depths of the ocean. As a result, the branch of underwater archaeology was created to search for shipwrecks and other artifacts on the ocean floor. Underwater archaeology’s role has increased in recent years as it allows archaeologists to more accurately interpret the past by supplementing information gained through traditional land excavations.
Divers cannot put the equipment on and immediately dive in. Before diving there are a series of procedures the diver and their partners must do before going down. In addition, the further down the diver dives the more pressure pressing down on the diver which lessens the amount of oxygen in the scuba tank. Therefore, the further down the diver dives the less time the diver can spend on the bottom. But now, by far the largest group of divers is “Recreational Divers”. These dives are practiced at depths of less than 130 feet, from these depths, divers can make a straight ascent to the surface. Diving beyond this limit requires advanced training. Also, when diving the diver must take into account the amount of time spent descending and ascending in the water. If the diver descends too quickly the pressure can deflate their lungs and cause problems. Similarly, if they ascend too quickly nitrogen bubbles can form under the diver’s skin causing bends or decompression sickness. This sickness can be extremely harmful and possibly fatal. Lastly, a dive watch or computer is needed to calculate the amount of oxygen left in their tank and the depth. Dive computers help the divers be aware of their conditions and keep them
With smiles on our faces we cast our wisely selected lures into the ocean, but we then encountered our first problem of saltwater fishing. Our lures wouldn’t sink. As soon as they hit the water, the ocean current would just buoy them to the surface and, soon after, down current into the line of a nearby fisherman. Improvising our rigs, we dug the heaviest weights out of our tackle boxes and clamped them onto our lures. Sure enough, we got our lures underwater and under control.
Throughout this essay we have had a chance to look at the two major types of underwater diving. We have a better understanding of the differences in the equipment used, the locations that each may be performed, and the career opportunities available to a person with the proper credentials.
Review: The opportunity and endeavor of exploring the Earth’s oceans can reap great rewards for mankind and unravel many of the mysteries that the Earth has left to discover.
“How and why is it that I do not describe my method for remaining underwater and how long I can remain there without coming up for air? I do not wish to divulge or publish this because of the evil nature of men, who might use it for murder on the sea-bed.” – Leonardo Da Vinci [1].
No Author Presented. "Deep Sea Mining." Deep Sea Mining. N.p., n.d. Web. 28 Mar. 2014. .
Allows divers to dive deeper and stay submerged longer. Scuba comes a long way from other forms of diving by using an air-tank and regulator. This is what allows them to stay under longer and dive deeper. Scuba originally began with military and commercial applications, where it is still used today. But now, by far the largest group of divers is “Recreational Divers”. These dives are practiced at depths of less than 130 feet, from these depths, divers can make a straight ascent to the surface. Diving beyond this limit requires advanced training. (Lawrence, 4)
...ransportation and navigation challenge: Experts had made judgment related to sea behavior, weather condition. However navigation and transporting 19 precast segments at different open sea location in 24 hrs was a challenge.
Sailing has been around for millennia, and is considered to be one of the earliest and most environmentally friendly methods of water transport. Sailboats act as a method of transportation, exercise, and entertainment. These now more structurally developed and masterfully modeled ships have been engineered for efficiency, and these advancements have ensured durability and speed among modern sailboats. The great strength and ability of sailboats has given competitive owners the opportunity to participate in races, but generally sailboats have come to exist as more of a relaxed hobby. The expensive activity of sailing is demanding both physically and mentally, as it tests anticipative abilities and endurance. To understand the physics concepts at work in a sailboat is immensely advantageous, as it can generally improve one’s performance.
First, Robert Collier’s quote relates to the text “Careers in Robotics: A Case Study” because they had small efforts everyday to create underwater robots. Gill Jones and Ma...