Advantages of Natural Propulsive Systems

Abstract

The screw propeller has been the mainstay of marine propulsion, but new developments in biomimetic propulsion can provide advantages in terms of speed, maneuverability, efficiency, and stealth. The diversity of aquatic animals provides designs for drag-based paddling and lift-based oscillatory hydrofoils that can be incorporated into engineered propulsive systems for enhanced performance. While the screw propeller will remain the prominent propulsive device, the choice of alternative biomimetic propulsive systems will be dependent on particular applications, where the specifications dictate improved performance criteria.

Coordination of Multiple Robotic Fish With Applications to Underwater Robot Competition

“…In practice, the presented CPG model can be implemented as a four-part system involving an amplitude regulator in (1), an offset regulator in (2), a phase and frequency regulator in (3), and an output magnitude calculator in (4). The phase of each oscillator is impacted by the other oscillators, while the other variables including the frequency described in (3) are independent.…”

“…In nature, aquatic animals including fish and cetaceans are endowed with a variety of morphological and structural features for moving through water with remarkable speed, maneuverability, efficiency, and stealth [3]. Although the screw propeller is considered as an effective engineered propulsive device, it has certain limitations related to cavitation, a small operational range of maximum efficiency, reliance on control surfaces maneuvering, and a detectable and identifiable acoustic signature [4]. Fishlike propulsion mechanism is thereby considered a viable alternative to conventional rotary propellers for marine propulsion.…”

Towards a miniature self-propelled jellyfish-like swimming robot

“…Among these parameters, a i , f i , i , and k i are the key ones set in the control algorithm. They are also mutually constrained by equation (2). Considering the coherence and coordination of the four legs, the oscillation frequency of each leg remains the same, that is…”

“…1 Among underwater robots, swimming robots have significant potential for study of marine life, monitoring oceanic environments, and underwater operations. [2][3][4][5][6][7] As a specific sea creature, jellyfish has a soft body, which is found in the waters all over the world. Owing to low metabolic rate, jellyfish has the ability to move vertically without expending much energy, while it passively depends on ocean current, tides, and wind for horizontal movements.…”

On a Miniature Free-Swimming Robotic Fish with Multiple Sensors

“…Fortunately, real fish offer design and control paradigms or solutions. To date, fish-inspired swimming robots (hereafter termed robotic fish) have shown superior performance in efficient propulsion and high manoeuvrability compared with conventional underwater vehicles propelled by rotary propellers [4][5][6][7][8][9][10].…”