Linearized Hovering Control With One or More Azimuthing Thrusters

Abstract

We propose a simple method of control system design for marine vehicles with one or more azimuthing propulsors, and specifically for the case where the speed of the actuator is on the same time scale as the plant dynamic response, thus making the assumption of a separation of time scales invalid. By setting a fixed, regular azimuth trajectory, the control problem is simplified sufficiently to allow a fully linear design approach, for which bandwidth achieved, robustness, and disturbance and noise rejection, will be more tangible than in the nonlinear cases. Several simulation examples are presented for a new vehicle that is in development; the approach would apply directly to the cases of multiple propulsors and dynamic positioning as well.