Bio-Inspired Fin-Based 3D Maneuvering For Underwater Robots

In the field of robot development, nowadays, bio-inspired solutions are on the ascendancy. This is due to many reasons, but we can mainly summarise them through the ideal of pursuing an engineering ‘leitmotif’: improving performance and overcome current technologies. In fact, if we look at living organisms as autonomous systems, they are, without any doubt, the most sophisticated robust and adaptable systems we know. The living beings we see every day are the result of millions of years of evolution, they have achieved a very high level of adaptation to their environment, and often their solutions to survive (in terms of body structure or behaviour) are the most efficient imaginable [8]. So, it is immediate to think about a kind of reverse engineering applied to the animal world to understand and exploit its characteristics in order to find new, alternative and efficient solutions for modern challenges. All those branches of engineering concerned with developing new technologies on the basis of biodiversity observation can be framed in this light. Obviously, in the world of underwater robotics, the main source of inspiration are fishes. To date, however, there are many problems that slow down the development of this field, mainly related to the limitations of current materials and technologies and to the difficulties associated with the underwater environment. The aim of this work is therefore to realise a complete model of a fish-inspired robot, without traditional actuators, controlled by means of innovative fins that use SMA wires to generate motion. Specifically, the objective is to assess the magnitude of the torques generated by the fins’ movements and to test the feasibility of a control strategy based on the superposition of the individual measured effects. The document is structured with a first chapter in which an exhaustive state of the art on bio-inspired robotics is presented. Then, in the second and third chapter, the technical features related to the design and realisation of the model and the experiments are explained. Finally, the fourth chapter shows and comments on the results obtained.