Underwater, supercavitating vehicles can achieve higher speeds than conventional
submarine vehicles due to the drag reduction result of the vehicle-fluid isolation. Re-
search on the control of high speed supercavitating vehicles has led to theoretical so-
lutions; however, validation and testing of control laws to drive the vehicle motion are
expensive, complex and have not been presented in the open literature.
This thesis presents an approach to the experimental validation of control systems
for a supercavitating test vehicle in the longitudinal plane. The supercavitating vehi-
cle considered in this thesis consists of a cylindrical body with a disk cavitator and
two lateral, sweptback, wedge fins. The control validation platform enables the use of
the high speed water tunnel located at the Saint Anthony Falls Laboratory to recre-
ate realistic flight scenarios including the effect of ocean waves on the vehicle. The
test platform uses the hydrodynamic forces produced by the fluid-vehicle interaction,
embedded flight computer, and analytical equations of motion to test the closed-loop
system performance in real time. The equations of motion for the test vehicle are de-
rived based on experiments in which the effect of perturbed flow on the vehicle motion
is also considered. A controller for the test vehicle is synthesized using H-infinity op-
timization. Water tunnel tests successfully validated the supercavitating vehicle model
and controller. The objectives were tracking of pitch angle reference commands and
rejection of disturbances produced by an oscillating foil gust generator.
The experimental results show the accuracy of the vehicle modeling and control
design as well as the effect of the perturbed flow on the closed-loop system performance.
The experience gained from this work enabled the introduction of the next generation test platform capable to capture planing phenomena.