Highly maneuverable biorobotic underwater vehicles

Abstract

After receiving only a trickle of interest over the past 50 years or so, biolocomotion has more recently attracted broader attention. In this chapter, biology-inspired highly maneuverable underwater vehicles (of ≈1m length scale) that have achieved some degree of maturity are reviewed. Primarily, the Naval Undersea Warfare Center (NUWC) works are described. The nonlinear theoretical foundation of animal-inspired hydrodynamics and control is summarized. Low-speed propulsion (including hovering and maneuvering), control, and integration with sensors are considered. High-lift flapping-fin propulsion technology, cycle-averaged and olivo-cerebellar temporal control, integration with interaural timedifferencing bio-sonar, and basin demonstration of utility are discussed. While numerous variables affect the mechanisms and integration of actuators, controllers, and sensors, the principles of self-regulating nonlinear dynamics provide a common and simplifying framework for the development of biorobotic vehicles. The salient features of these vehicles and their control design laws are tabulated. These emergent, low-speed platforms complement existing higher speed naval capabilities and are not substitutes for any existing mature system; in this sense, their utility depends on the imaginative nature of future operation concepts - a process that is unpredictable. The greater potential of the biorobotics approach is limited by a serious lack of progress in so-called strong artificial muscle technology, as well as by a lack of understanding of nonlinear temporal control and sensing and how they should be integrated. Application to utility has been facilitated where understanding of the underlying science has been mathematically formulated, and such formulation needs to be more widely emulated.