Control theory has been applied to several domains where practical considerations are relevant. Robotics is a notable example of this. In most cases, mobile robotic systems are governed such that their behavior obeys to a defined motion. However, during their operations, it is conceivable that faults could occur. Indeed, this assumption has to be made in order to predict a possible malfunction ...

This paper describes the development of a five degree of freedom towed underwater vehicle designed for condition monitoring of undersea pipelines. Its innovative design, with 6 fins actuated by 5 motors adding heave and sway capabilities to the yaw, roll and pitch movements possible in traditional designs, is explained. The parameters influencing the stability and the design in general are anal...

We have constructed and operated a nanoscale linear motor powered by a single metal nanocrystal ram sandwiched between mechanical lever arms. Low-level electrical voltages applied to the carbon nanotube lever arms cause the nanocrystal to grow or shrink in a controlled manner. The length of the ram is adjustable from 0 to more than 150 nm, with extension speeds exceeding 1900 nm/s. The thermody...

A high-speed railway viaduct experienced a sustained heave at high rates after its construction. The pillars of the bridge are founded on an Eocene hard anhydritic-gypsiferous claystone by means of massive foundations. Field investigations identified an active layer below the piles’ tips where expansions occur as a result of gypsum crystal growth in discontinuities from supersaturated aqueous s...

Three models with different footing types were used to clarify the effect of heave plates on hydrodynamic behavior elastic response a flexible multicolumn floating offshore wind turbine (FOWT). The tested under regular waves, whose added mass, damping, and motion results compared numerical simulations by NK-UTWind WAMIT codes. As whole, attachment was responsible for increasing mass damping lev...

We examined the heave motion of a spherical buoy during free-decay drop test. A comprehensive approach was adopted to study oscillations involving experimental measurements and complementary numerical simulations. The experiments were performed in wave tank equipped with an array high-speed motion-capture cameras set high-precision gauges. simulations included three sets calculations varying le...

In this paper, a fully nonlinear unsteady potential flow method is used to predict added resistance, heave and pitch for the KVLCC2 hull in regular head waves at design speed. The presents decomposition of velocity wave field an adaptive grid refinement. A formulation acceleration obtain pressure. To improve computational efficiency, Barnes-Hut algorithm introduced. dependency study on impact d...

This paper presents a modification to L1 adaptive control that allows for disturbances entering at the output and application of this control strategy to Managed Pressure Drilling with harmonic disturbances representing the heave motion of a floating drilling rig. By incorporating the disturbance at the output into the reference model, it is shown that the L1 adaptive control structure can be l...

We conduct full-scale experimental validation and comparison of three different nonlinear attitude observers, two of them with inherent heave estimation, in two different operational scenarios encountered by an offshore vessel in the North Sea. Two different microelectro-mechanical inertial measurement units are the primary sensors for driving the nonlinear observers, which are aided by gyrocom...