Control Synthesis and Adaptation
for an Underactuated Autonomous Underwater Vehicle

N.E. Leonard

The motion of an autonomous underwater vehicle (AUV) is controllable even with reduced control authority such as in the event of an actuator failure. In this paper we describe a technique for synthesizing controls for underactuated AUV's and show how to use this technique to provide adaptation to changes in control authority. Our framework is a motion control system architecture which includes both feedforward control as well as feedback control. We confine ourselves to kinematic models and exploit model nonlinearities to synthesize controls. Our results are illustrated for two examples, the first a yaw maneuver of an AUV using only roll and pitch actuation, and the second a ``parking maneuver'' for an AUV. Experimental results for the yaw maneuver example are described.

Postscript Version (29 pages postscript)