Robotic Fish Locomotion & Propulsion in Marine Environment: A Survey

Fish Robots, especially bio-inspired robots that mimic biological creatures are gaining popularity in research field. Mostly the mathematical modeling, controlling of their kinematics, dynamics, swimming mechanism are main areas of interest. An intelligent Aquatic Robot generally exhibits three major functions, viz. guidance, control, and navigation. This paper is a discussion about the gradual development of these Fish Robots and their swimming, propulsion, locomotion mechanisms etc. that involved. The main objective is to bring forward a conclusive, relevant and useful conclusion from existing literature so as to boost interest in the emerging area of these Fish Robots. The fish locomotion is one of the prime inspirations of Fish Robots, and most of the bio-inspired Fish Robots are designed by mimicking the fish swimming profiles. The fish swimming can broadly be classified as Body and/or Caudal Fin (BCF)movements or using Median and/or Paired fin (MPF)propulsion. The swimming profile and characteristics of mostly used propulsion mode of various Fish Robots are discussed here in this paper. It is known that robotic fish propulsion mechanism is very complex to realize in models, it involves several aspects such as shape of the robot, hydro-dynamics involved, pattern of movement, control system involved, mechanical properties, location of various mechanical components and properties of the material used etc. Various structures and materials used in existing Fish Robots and significance of selection are reviewed. In future we look forward to develop better alternative techniques for locomotion and maneuvering.