In drilling operations, the interaction of the drillstring with the borehole leads to vibrations
affecting the performance and increasing the drilling cost. The development of controllers to …

In drilling operations, the drillstring interaction with the borehole gives rise to a wide variety
of undesired oscillations. The main types of drilling vibrations are torsional (stick-slip), axial …

Vibrations in mechanical systems are oscillations occurring without being intentionally
provoked. They often have detrimental effects on the system performance and may cause …

In drilling operation, a wide variety of oscillations causing failures often arise. Torsional
vibrations (stick-slip) are originated by the cutting device (bit) motion, these vibrations in turn …

This article proposes a control strategy to stabilize the axial–torsional dynamics of a
distributed drill-string system. An infinite-dimensional model for the vibrational dynamics of …

We develop an observer-based boundary controller for the rotary table to suppress stick–slip
oscillations and to maintain the angular velocity of the drill string at a desired value during a …

The oscillations occurring during the drilling process constitute a major problem to solve in
the oil extraction industry. Drilling vibrations most frequently occurring in the field are …

This paper deals with the exponential stability analysis of switched neutral systems under
certain state-dependent switching rules with nonlinear perturbations bounded in magnitude …

Part of the process of exploration and development of an oil field consists of the drilling
operations for oil and gas wells. Particularly for deep water and ultra deep water wells, the …

We discuss boundary control of a wave equation with a non-linear anti-damping boundary
condition. We design structured finite-dimensional-output feedback controllers that stabilize …