Depth control of an underwater vehicle using linear parameter-varying techniques

The applicability of employing a linear parameter-varying (LPV) control to an underwater vehicle is investigated and compared to that of using a linear time-invariant robust control. The underwater vehicle is first modeled into a polytopic-type LPV system with speed variation. Then LPV controllers based on output feedback are designed which achieve specified performances such as bounded L₂-induced norm and closed-loop pole clustering constraints for frozen linear time-invariant models. A parameter-dependent weight is investigated in the LPV synthesis. It is shown that the designed controller performs well over the entire operating range by computer simulation.