Experimental results with value function based control of an AUV

This paper reports experimental results obtained with a value function based path following controller for Autonomous Underwater Vehicles (AUV). The value functions are computed using numerical methods for the dynamic programming (DP) equations. We consider the case of planar operation of an AUV with actuation surfaces (fins). A reduced nonlinear model with 4 state variables is considered: cross-track error, angle with respect to path, angular velocity and fin's position. The objective of our control approach is twofold: to ensure given hard constraints on the maximum cross-track error in the presence of bounded disturbances; to provide a balance between the controller performance and the rate of change in the fin's position, in order to avoid premature wear of the servomotors. The underwater experiments are performed with an AUV from Porto University.