Simulation and control of an underwater hexapod robot

Abstract

AQUA is an underwater hexapod robot which uses its paddles to propel itself and to control its orientation. The use of oscillating paddles for propulsion and control represented a novel and challenging problem, which motivated the need for a simulation of the motion of the robot based on its paddle oscillations. The most difficult aspect of this simulation was the characterization of the forces generated by the paddles oscillating in the water. In this work, a model predicting the forces produced by an oscillating rigid paddle was developed and validated experimentally. Also, the forces produced by a flexible fin were determined experimentally and were compared to those generated by the rigid paddle. Rigid paddle and flexible fin experiments were performed on an experimental setup, which was designed and built to measure the forces and torques produced by a paddle oscillating in a water tank. Finally, a simulation of the AQUA robot was developed, based on the validated rigid paddle model.