Control of an underwater vehicle using H∞ synthesis

The authors present the results of a design exercise in which recent developments in H_∞ synthesis theory were applied to the design of a controller for an autonomous underwater vehicle (AUV). The problem statement requires the design of a position and attitude control system for the vehicle to achieve precise trajectory following. The major steps in the synthesis procedure were as follows. A detailed nonlinear dynamic model of the AUV was derived, and an operating point for nominal design was selected. After linearization around the nominal operating point, a multivariable controller was designed using standard techniques of H_∞ theory. The performance of the controller was evaluated in simulations with a full nonlinear model of the vehicle