Adequate six degree of freedom control of astable unmanned underwater vehicles

Astable unmanned underwater vehicles (UUVs) are excellent in underwater maneuverability but challenging in terms of control. An existing Lyapunov based adaptive nonlinear vehicle controller is enhanced by replacing its adaptation law with composite adaptation common in robotics. A novel online trajectory scaling algorithm is developed to prevent actuator saturation and a Matlab based graphical simulator is designed to be a test bed on which control performance is evaluated.