Int. J. of Applied Mathematics, Computational Science and Systems Engineering



H∞ Based on Adaptive Fuzzy Control design for Four Degree-of-Freedom of Drill-String System

Author(s): Hsuan-Yi Chen, Mansour Karkoub, Tzu-Sung Wu

Abstract: The reduced-order models of a flexible drill-string systems allow for radial, bending, and torsion motions with stickslip interactions between the drill-string and the outer shell is highly nonlinear and classified as under-actuated. Therefore, the drill-string system are very complex mechanical systems and have been the subject of research investigations for several decades. In this paper, a H1 based adaptive fuzzy control is proposed to control the four degree-of-freedom of the drill-string system. The advantage of employing an adaptive fuzzy system is using linear analytical results in place of estimating the dynamics of the drill-string system with an online update law. A robust control law combined with a variable structure (VS) and H1 control scheme is derived based on a Lyapunov criterion and the Riccaiinequality to overcome the system uncertainties, and external disturbances so that all signals of the closed-loop system are uniformly ultimately bounded (UUB). Simulations show that the proposed control scheme is effective in reducing the phenomenon of the drill-string system hitting with outer shell due to the drillstring system bending such that the rotation of a drill-string keep close to the radial center.

Keywords: Nonlinear systems; adaptive fuzzy control; H∞ control; VS scheme; drill-string system.

Pages: 48-55


Ιnt. J. of Applied Mathematics, Computational Science and Systems Engineering (published by International Academic Publications)


"International Academic Publications", 1666 Kennedy Causeway #412, North Bay Village, Miami, Florida, United States of America.



+1 914 2787705