Design of a bilinear robust controller for a hydrostatic driver

The aim of this paper is to present a new method of designing a bilinear robust controller in a nonlinear system. This is an alternative and advanced method to control a shaking system with a heavy mass showing troublesome nonlinear effects. For this design procedure, a keel driven by a hydro-rotating driver is given. As the first step, the keel is physically modeled with a number of the limited masses. and based on a physical model the dynamic mathematical model is derived using the finite element method in respect to the Hamilton principle; thus, the system is represented by various subsystems. This is a reference system for the given physical system. Based on a physical model for rotating and transit behavior induced from movement phenomena measured at the bearings on the driver. Then the system is transformed into the bilinear system and based on this system, an bilinear elementary observer is designed to control the behavior of the keel in a yacht. The information for the given system are the measurements of the torque in the driver, velocity and fluid in the valves.