A system identification based approach for pulsed eddy current non-destructive evaluation

This paper is concerned with the development of a new system identification based approach for pulsed eddy current non-destructive evaluation and the use of the new approach in experimental studies to verify its effectiveness and demonstrate its potential in engineering applications

Ensemble tensor decomposition for infrared thermography cracks detection system

Eddy Current Pulsed Thermography (ECPT) has received much attention for its high sensitive of detectability on cracks with infrared cameras. However, when it comes to the detection in a movement way, it remains as challenges. This paper proposed an ensemble tensor decomposition to extract weak target signal of infrared thermography videos for cracks detection. The proposed algorithm jointly models the background and foreground tensor patterns as well as removing the ghosting. In order to verify the effectiveness and robustness of the proposed method, experimental studies have been carried out by applying electromagnetic thermal imaging system for cracks detection on samples with different geometry. The results of the experiments have indicated that the proposed method has significantly enhanced the contrast ratio between the defective regions and the non-defective regions

Measurement of event-shape observables in Z→ℓ+ℓ− events in pp collisions at √ s=7 TeV with the ATLAS detector at the LHC

Event-shape observables measured using charged particles in inclusive $Z$-boson events are presented, using the electron and muon decay modes of the $Z$ bosons. The measurements are based on an integrated luminosity of $1.1 {\rm fb}^{-1}$ of proton--proton collisions recorded by the ATLAS detector at the LHC at a centre-of-mass energy $\sqrt{s}=7$ TeV. Charged-particle distributions, excluding the lepton--antilepton pair from the $Z$-boson decay, are measured in different ranges of transverse momentum of the $Z$ boson. Distributions include multiplicity, scalar sum of transverse momenta, beam thrust, transverse thrust, spherocity, and $\mathcal{F}$-parameter, which are in particular sensitive to properties of the underlying event at small values of the $Z$-boson transverse momentum. The Sherpa event generator shows larger deviations from the measured observables than Pythia8 and Herwig7. Typically, all three Monte Carlo generators provide predictions that are in better agreement with the data at high $Z$-boson transverse momenta than at low $Z$-boson transverse momenta and for the observables that are less sensitive to the number of charged particles in the event.Comment: 36 pages plus author list + cover page (54 pages total), 14 figures, 4 tables, submitted to EPJC, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2014-0

Inverse kinematic analysis for triple-octahedron variable-geometry truss manipulators

In this paper, a new triple-octahedron variable-geometry truss manipulator is presented. Its inverse kinematic solutions in closed form are studied. An input-output displacement equation in one output variable is derived. The solution procedure is given in detail. A numerical example is illustrated

Virtual Reality Based Robot Graphic Simulation and Virtual Manufacturing System

This paper reports research into an interface between industry robots and Virtual Reality systems and creates a virtual robot for robot arm simulation, control language conversion, physical communication, robot networking and teleoperation control. The paper is based on an integrated manufacturing networking software which includes a PUMA robot, a Lansing welding robot, and CNC machines. The aim of the research is to combine VR and robot technology for system testing, to establish VR based simulation workshop for defining and checking robot arm movement trajectory, eliminating the chance of potential collision. The paper also presents a system that can interpret the recognised operations into operator-level commands using task-dependent interpretation rules and a world model. A robot executes the defined task in the workspace by replicating operator’s movements in the virtual workspace

Data fusion for defect characterisation using a dual probe system

We present recent work on a dual probe system containing electromagnetic acoustic transducers (EMATs) generating and detecting surface ultrasonic waves, and a pulsed eddy current (PEC) probe. This system is able to detect and size surface and near-surface defects in electrically conducting samples by looking at changes in the detected signal for each probe. By combining the information from each probe using a weighted logic function for data fusion, it is possible to both classify and size defects, with increased reliability. By combining the data in this way one obtains information about the defects which is not available when using either probe in isolation. Typical results on steel and aluminium samples are presented, along with information about the data fusion function. The dual probe and data fusion routine has been demonstrated to work at manual-scanning speeds, with higher speeds possible following some simple improvements to the system

Visualisation based feedback control for multiple sensor fusion

This paper presents a new approach for adaptive weighting schemes for multiple sensor fusion by using visualisation feedback control. A visualisation schema is used to coordinate the information content capture of different features from multiple sensors. The end-users can interact with the training sample distribution to obtain weights for the sensor data fusion and decision making. Based on the proposed fusion approach, some applications such as audiovisual biometric authentication and multi-modal surface measurement are discussed

Study of magnetic sensors for pulsed eddy current techniques

In this study we compare the suitability of a Hall device and a GMR sensor as the sensing device in pulsed eddy current systems. The comparative study is carried out by using both experimental results and manufacturers' data. The factors to be analysed are sensitivity, noise level, and operational bandwidth. Conclusions are given following the analysis of the data