Search results for " Computer Science"
showing 10 items of 3983 documents
Automated Kick Control Procedure for an Influx in Managed Pressure Drilling Operations
2016
Within drilling of oil and gas wells, the Managed Pressure Drilling (MPD) method with active control of wellbore pressure during drilling has partly evolved from conventional well control procedures. However, for MPD operations the instrumentation is typically more extensive compared to conventional drilling. Despite this, any influx of formation fluids (commonly known as a kick) during MPD operations is typically handled by conventional well control methods, at least if the kick is estimated to be larger than a threshold value. Conventional well control procedures rely on manual control of the blow out preventer, pumps, and choke valves and do not capitalize on the benefits from the instru…
Modeling and Parameter Identification of Deflections in Planetary Stage of Wind Turbine Gearbox
2012
The main focus of this paper is the experimental and numerical investigation of a 750[kW] wind turbine gearbox. A detailed model of the gearbox with main shaft has been created using MSC.Adams. Special focus has been put on modeling the planet carrier (PLC) in the gearbox. For this purpose experimental data from a drive train test set up has been analyzed using parameter identification to quantify misalignments. Based on the measurements a combination of main shaft misalignment and planet carrier deflection has been identified. A purely numerical model has been developed and it shows good accordance with the experimental data.
odeling of Human Arm Energy Expenditure for Predicting Energy Optimal Trajectories
2011
Human arm motion can inspire the trajectory planning of anthropomorphic robotic arms to achieve energy-efficient movements. An approach for predicting metabolic cost in the planar human arm motion by means of the biomechanical simulation is proposed in this work. Two biomechanical models, including an analytical model and a musculoskeletal model, are developed to implement the proposed approach. The analytical model is developed by modifying a human muscle expenditure model, in which the muscles are grouped as torque providers for computation efficiency. In the musculoskeletal model, the predication of metabolic cost is conducted on the basis of individual muscles. With the proposed approac…
A robust fault detection design for uncertain Takagi-Sugeno models with unknown inputs and time-varying delays
2013
Abstract This paper investigates the problem of robust fault detection system design for a class of uncertain Takagi–Sugeno (T–S) models. The system under consideration is subject to unknown input and time-varying delay. The fault detection system is designed such that the unknown input is thoroughly decoupled from residual signals generated by the fault detection system. Furthermore, the residual signals show the maximum possible sensitivity to the faults and the minimum possible sensitivity to the external disturbances. The model matching approach is utilized to tackle the effects of parametric uncertainties in the model of the system. The design procedure is presented in terms of Linear …
A structured filter for Markovian switching systems
2014
In this work, a new methodology for the structuring of multiple model estimation schemas is developed. The proposed filter is applied to the estimation and detection of active mode in dynamic systems. The discrete-time Markovian switching systems represented by several linear models, associated with a particular operating mode, are studied. Therefore, the main idea of this work is the subdivision of the models set to some subsets in order to improve the detection and estimation performances. Each subset is associated with sub-estimators based on models of the subset. In order to compute the global estimate and subset probabilities, a global estimator is proposed. Theoretical developments ba…
Semiactive vibration control of nonlinear structures through adaptive backstepping techniques withH∞performance
2011
This article presents a new approach to the vibration mitigation problem in structures subject to seismic motions. These kinds of structures are characterised by the uncertainties of the parameters that describe their dynamics, such as stiffness and damping coefficients. Moreover, the dampers used to mitigate the vibrations caused by earthquakes are usually nonlinear devices with frictional or hysteretic dynamics. We propose an adaptive backstepping controller to account for the uncertainties and the nonlinearities. The controller is formulated in such a way that it satisfies an H∞ performance. It is designed for a 10-storey building whose base is isolated with a frictional damper (passive …
Past, Present and Future of Process Control at Xstrata Nikkelverk
2009
MIC celebrates its 30th anniversary in 2009 and Xstrata Nikkelverk celebrates its 100th anniversary in 2010. Both anniversaries are certainly worth celebrating and with this article Xstrata Nikkelverk salutes MIC at this special occasion. This article is about process control developments at Xstrata Nikkelverk during the last 40 years. We also give an overview of the current status and a view on the current and future trends of process control at the Nikkelverk renery.
daptive Backstepping Control of Nonlinear Hydraulic-Mechanical System Including Valve Dynamics
2010
Published version of an article from the journal: Modeling Identification and Control. Also available from publisher: http://dx.doi.org/10.4173/mic.2010.1.3 The main contribution of the paper is the development of an adaptive backstepping controller for a nonlinear hydraulic-mechanical system considering valve dynamics. The paper also compares the performance of two variants of an adaptive backstepping tracking controller with a simple PI controller. The results show that the backstepping controller considering valve dynamics achieves significantly better tracking performance than the PI controller, while handling uncertain parameters related to internal leakage, friction, the orifice equat…
A pedagogical flight simulator for longitudinal airplane flight
2009
This article presents a bi-dimensional model of flight and describes the implementation of a flight simulator able to describe the different phases of longitudinal flight of a real airplane. After identifying the relevant physical variables, the equations of motion are written and solved using a numerical integration method. Using computer simulations, flight paths and time evolution of the kinematics variables are analyzed for a complete flight of a light commercial airplane. The simulations take into account and reproduce the basic actions of a pilot to control the flight. The main maneuvers involved in pilotage are also predicted and explained in terms of model parameter variations induc…
A Virtual Milling Machine Model to Generate Machine-Monitoring Data for Predictive Analytics
2015
Real data from manufacturing processes are essential to create useful insights for decision-making. However, acquiring real manufacturing data can be expensive and time consuming. To address this issue, we implement a virtual milling machine model to generate machine monitoring data from process plans. MTConnect is used to report the monitoring data. This paper presents (1) the characteristics and specification of milling machine tools, (2) the architecture for implementing the virtual milling machine model, and (3) the integration with a simulation environment for extending to a virtual shop floor model. This paper also includes a case study to explain how to use the virtual milling machin…