Visual Sensor’s Assisted Autonomous Planing Craft for Scientific and Research Applications
To promote the development and operation of an autonomous small planing crafts, the capability to predict in real time the accelerations and motions the craft is expected to develop based on the knowledge of the incoming waves is much required. As part of this a nonlinear mathematical model for the simulation of motions and accelerations of planing monohulls in seaway having a constant or variable deadrise angle, in head or following waves has been formulated. This model, based on the 2-dimensional strip theory, improves previously developed models and provides accurate results for the acceleration, velocities and expected motions of a planing craft in the vertical plane and in the time domain. The sectional hydromechanic forces are determined by the theory of wedge penetrating water surface. The sectional wetted breadth and immersion are directly integrated into the expressions for the hydromechanic forces. A near transom pressure correction affecting both the hydrostatic and the hydrodynamic terms of the load distribution is introduced. The dynamic drag force is calculated based on a semi-empirical model. To validate and calibrate the developed model a JetSki platform is fitted for remotely controlled operation and is instrumented with an Inertial Measurement unit (IMU) to log the linear and angular accelerations and the angular attitude of the craft. The incoming waves are measured by a separately deployed buoy. The model based computed wave induced heave, pitch and vertical accelerations has been validated with these experimental data and the differences are addressed. Comparison of the computed vertical acceleration with various classification societies' semi empirical relations is also presented and examined. Visual sensors assisted algorithm to support in the selection of a feasible speed and navigation path in rough seas will be integrated into the existing platform to support the craft's autonomous operation.
Keywords - Hydrodynamics, Unmanned, Mathematical Model, Planing Craft, Seakeeping, Time Domain Simulation.