Browsing by Author "Bayliss, Martin T."
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Item Open Access Attitude control system for directional drilling bottom hole assemblies(Iet, 2012-05-31T00:00:00Z) Panchal, Neilkunal; Bayliss, Martin T.; Whidborne, James F.A general approach for the attitude control of directional drilling tools for the oil and gas industry is proposed. The attitude is represented by a unit vector, thus the non-linearities introduced by Euler angle representations are avoided. Three control laws are proposed, and their stability is proven. Their behaviour is tested by numerical simulation. The merits of the laws from an engineering perspective are highlighted, and some details for the implementation of the laws on directional drilling tools are provided.Item Open Access Bilinear modelling and bilinear PI control of directional drilling(IEEE, 2016-11-10) Inyang, Isonguyo J.; Whidborne, James F.; Bayliss, Martin T.This paper presents the design of an inclination- and azimuth-hold controllers and their subsequent stability and performance analysis for directional drilling tools as typically used in the oil industry. Using an input transformation developed in earlier work that partially linearizes and decouples the plant dynamics of the directional drilling tool, a bilinear model of the directional drilling tool is developed and is used as the basis for Bilinear PI controller design. Results for a transient simulation of the proposed BPI controller are presented and compared with that of the PI controller of the earlier work. It is presented that BPI controller gives more consistent responses over a broader operating range compared to the PI controller. In addition, the effect of time delay on the feedback measurements with respect to the stability and performance is investigated in the simulations.Item Open Access Directional drilling attitude control with input disturbances and feedback delay(Elsevier, 2017-10-18) Inyang, Isonguyo J.; Whidborne, James F.; Bayliss, Martin T.This paper presents a general approach for the attitude control of directional drilling tools for the oil and gas industry. It extends the recent work where a kinematic bilinear model of the directional drilling tool was developed and used as the basis for Constant Build Rate (CBR) controller design. The CBR controller in combination with a modified Smith Predictor (SP) is implemented for the attitude control of the directional drilling. The results of a transient simulation of the proposed modified SP-CBR controller are presented and compared with that from the CBR controller of the earlier studies. It is shown that the modified SP-CBR controller significantly reduces the adverse effects of input disturbances and time delay on the feedback measurements with respect to stability and performance.Item Open Access Modelling and control of the roll-stabilised control unit of a rotary steerable system directional drilling tool(IET, 2019-04-26) Alturbeh, Hamid; Whidborne, James F.; Luk, Patrick Chi-Kwong; Bayliss, Martin T.A directional drilling tool control unit whose design is based on servo control of a rotary valve using the roll-stabilised instrumented system approach has been successfully used in oil fields for over 20 years. Here, field-oriented control (FOC) is applied to cascaded voltage regulation and servo control using an open-loop plant model of the roll-stabilised control unit. The servo control is applied to the rotary valve so that drilling mud is ported in a geostationary direction despite the rotation of the drill string and the bottom hole assembly of the rotary steerable system. Voltage regulation is applied in order to provide a DC voltage bus for the servo control of the valve. A torquer or alternator, which is a type of permanent magnet synchronous machine, is the core of the roll stabilised control unit. So, a mathematical model of the torquer is derived. An FOC scheme is proposed for servo control and to provide a DC regulated voltage using the torquers. The algorithm is tested in MATLAB/Simulink.Item Open Access The numerical modelling of elastomers(Cranfield University, 2003) Bayliss, Martin T.; El-Zafrany, A.This thesis reports onreview and research work carried out on the numerical analysis of elastomers. The two numerical techniques investigated for this purpose are the finite and boundary element methods. The finite element method is studied so that existing theory is used to develop a finite element code both to review the finite element method as applied to the stress analysis of elastomers and to provide a comparison of results and numerical approach with the boundary element method. The research work supported on in this thesis covers the application of the boundary element method to the stress analysis of elastomers. To this end a simplified regularization approach is discussed for the removal of strong and hypersingularities generated in the system on non-linear boundary integral equations. The necessary programming details for the implementation of the boundary element method are discussed based on the code developed for this research. Both the finite and boundary element codes developed for this research use the Mooney-Rivlin material model as the strain energy based constitutive stress strain function. For validation purposes four test cases are investigated. These are the uni-axial patch test, pressurized thick wall cylinder, centrifugal loading of a rotating disk and the J-Integral evaluation for a centrally cracked plate. For the patch test and pressurized cylinder, both plane stress and strain have been investigated. For the centrifugal loading and centrally cracked plate test cases only plane stress has been investigated. For each test case the equivalent results for an equivalent FEM program mesh have been presented. The test results included in this thesis prove that the FE and BE derivations detailed in this work are correct. Specifically the simplified domain integral singular and hyper-singular regularization approach was shown to lead to accurate results for the test cases detailed. Various algorithm findings specific to the BEM implementation of the theory are also discussed.Item Open Access Numerical modelling of elastomers using the boundary element method(Wiley, 2004-08-18) Bayliss, Martin T.; El-Zafrany, A.The FEM analysis of hyper elastic, elastomeric materials has been formulated and implemented for various material models (strain energy functions) over the years. More recently, the analysis of elastomeric materials has been attempted in the boundary element method. This has been achieved by the addition of non-linear domain terms to the basic linear boundary element equation. These non-linear domain terms require the evaluation of the displacement derivative components directly from displacement derivative boundary integral equations. In the solution to the boundary problem it is required to regularize the different types of singularities occurring in the system of non-linear boundary integral equations. This paper discusses the necessary theory for the boundary element method as applied to elastomers and presents a comparison between semi-analytical and numerical solutions for various test cases.