Design study of flapping foil propulsion for an Odyssey Class AUV

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002.Includes bibliographical references (leaves 56-57).A design study was conducted to examine the feasibility of implementing fish-like flapping foil propulsion on an Odyssey Class autonomous underwater vehicle (AUV). Theoretically, fish-like propulsion offers higher efficiencies, greater maneuverability, and the potential for faster accelerations than the conventional propulsion system currently in use on the Odyssey Class AUV. Previous laboratory research has shown promising results, and retrofitting an Odyssey Class AUV with a flapping foil is a cost-effective way to step up the learning curve toward applying this technology in a field setting. Based primarily on MIT's RoboTuna research on the swimming motions of fish, the proposed design hopes to achieve a speed of 1.5 m/s. Oscillating two tail links independently at a tail flapping frequency of about 1 Hz should provide this performance. The links are driven with DC brushless motor systems through a Scotch yoke linkage and a linear actuator. Pitch and roll motion is accomplished with the addition of servo actuated pectoral fins, while dorsal and anal fins provide additional directional stability. A variety of motion schemes were contemplated, but the final design was chosen with an emphasis on simplicity, practicality, and robustness for use in a field setting.by Rafael A. Mandujano.S.B

Force-Canceling Mixer Algorithm for Vehicles with Fully-Articulated Radially Symmetric Thruster Arrays

A new type of fully-holonomic aerial vehicle is identified and developed that can optionally utilize automatic cancellation of excessive thruster forces to maintain precise control despite little or no throttle authority. After defining the physical attributes of the new vehicle, a flight control mixer algorithm is defined and presented. This mixer is an input/output abstraction that grants a flight control system (or pilot) full authority of the vehicle\u27s position and orientation by means of an input translation vector and input torque vector. The mixer is shown to be general with respect to the number of thrusters in the system provided that they are distributed in a radially symmetric array. As the mixer is designed to operate independently of the chosen flight control system, it is completely agnostic to the type of control methodology implemented. Validation of both the vehicle\u27s holonomic capabilities and efficacy of the flight control mixing algorithm are provided by a custom MATLAB-based rigid body simulation environment

Locomation strategies for amphibious robots-a review

In the past two decades, unmanned amphibious robots have proven the most promising and efficient systems ranging from scientific, military, and commercial applications. The applications like monitoring, surveillance, reconnaissance, and military combat operations require platforms to maneuver on challenging, complex, rugged terrains and diverse environments. The recent technological advancements and development in aquatic robotics and mobile robotics have facilitated a more agile, robust, and efficient amphibious robots maneuvering in multiple environments and various terrain profiles. Amphibious robot locomotion inspired by nature, such as amphibians, offers augmented flexibility, improved adaptability, and higher mobility over terrestrial, aquatic, and aerial mediums. In this review, amphibious robots' locomotion mechanism designed and developed previously are consolidated, systematically The review also analyzes the literature on amphibious robot highlighting the limitations, open research areas, recent key development in this research field. Further development and contributions to amphibious robot locomotion, actuation, and control can be utilized to perform specific missions in sophisticated environments, where tasks are unsafe or hardly feasible for the divers or traditional aquatic and terrestrial robots

Bio-Inspired Robotics

Modern robotic technologies have enabled robots to operate in a variety of unstructured and dynamically-changing environments, in addition to traditional structured environments. Robots have, thus, become an important element in our everyday lives. One key approach to develop such intelligent and autonomous robots is to draw inspiration from biological systems. Biological structure, mechanisms, and underlying principles have the potential to provide new ideas to support the improvement of conventional robotic designs and control. Such biological principles usually originate from animal or even plant models, for robots, which can sense, think, walk, swim, crawl, jump or even fly. Thus, it is believed that these bio-inspired methods are becoming increasingly important in the face of complex applications. Bio-inspired robotics is leading to the study of innovative structures and computing with sensory–motor coordination and learning to achieve intelligence, flexibility, stability, and adaptation for emergent robotic applications, such as manipulation, learning, and control. This Special Issue invites original papers of innovative ideas and concepts, new discoveries and improvements, and novel applications and business models relevant to the selected topics of ``Bio-Inspired Robotics''. Bio-Inspired Robotics is a broad topic and an ongoing expanding field. This Special Issue collates 30 papers that address some of the important challenges and opportunities in this broad and expanding field