Paper Title
Robust Controller Design for the Mobile Drilling Tower

This paper presents modeling, simulation and controller design of drawworks sytem in a drilling tower during drilling and maneuvering operations. The relevant modeling involves; dynamically modeling of drill-string, drawworks, hook load, mud circulation, drill-bit, and the bottom-hole assembly. Position control is required for variable inertia system during maneuvering operation, and during drilling process; velocity control of the vertically penetrating string is needed under the uncertainties caused by the interaction of the drill bit and rock. The robust performance of the system is demonstrated by simulations of the proposed control system.