A Physicomimetic Approach to Distributed Intelligence and Control of Autonomous Watercraft

A square law of celestial mechanics is investigated as a driving virtual force law toward the development of swarms with distributes, i.e. not centralized, control and intelligence. It has been argued that decentralization of the control structure and task can enhance the robustness of the controllers involved and improve scalability. The approach in this work tackles the problem by adopting the concept of virtual forces which in this case follow the square law of attraction e.g. a nonlinear spring. The concept is adapted to the time and space, i.e. distance scales relevant to small, low-cost watercraft to be applicable. Various scenarios are investigated. All watercraft are assumed to have identical physical characteristics and dynamic responses but with small fluctuations and perturbations superimposed. Watercraft dynamics are simplified to model forward motion and rotation about the yaw axis; more detailed and precise models can also be used if desired or required. The local-loop controllers, which conventionally are called autopilots, ensure that the acceleration of the craft is adhering to the one dictated by the virtual, square law force field. Synthesis of the square law for the virtual force field involves amongst other feasibility of the derived governing dynamics as well as energy consumption, time to terminal conditions, etc.