Vehicle control in full unsteady flow using surface measurements .

摘要

This dissertation is the first comprehensive attempt to address a new engineering problem: control of a vehicle maneuvering in a full unsteady flow field. The approach to the solution is focused in three main areas: modeling of a vehicle maneuvering in a full unsteady flow field, control of a vehicle maneuvering in a full unsteady flow field, and synthesizing the unsteady fluid loads for use in vehicle control. To model a vehicle maneuvering in a full unsteady flow filed this dissertation develops the Coupled Fluid Vehicle (CFV) model in which the fluid, which is a sum of a finite number of spatially dependent velocity field whose contributions vary with time, is coupled to the vehicle rigid-body equations of motion. To control a vehicle maneuvering in a full unsteady flow field this dissertation develops the Fluid Compensation Control (FCC) strategy, which gives the control designer an opportunity to include the fluid states, in addition to the vehicle states, in the control law and an opportunity to balance reducing the fluid dynamic load through compensation and reducing the state error through regulation. To synthesize the unsteady fluid loads this dissertation has attempted to forward current work on the prediction of fluid loads from stagnation and separation point measurements by developing the Kutta principle, which says that the velocity around the vehicle is a smoothly varying function and that it is determined up to a multiplicative constant by its nodes (stagnation, separation, and reattachment points/lines), and by conducting an experiment in an attempt to determine the correlation of the fluid loads from the orientation and separation lines on a 3-dimensional bluff body.